Understanding Major and Trace Minerals

This is part two of the minerals lecture. So we are going to continue on with the major minerals that are found in large amounts in the body. Next, talking about phosphorus. So phosphorus is one of the most abundant minerals in the body, second only to calcium. The majority of the phosphorus in our body is found in bones and teeth. It combines with calcium to find to to make up this compound called hydroxyapatite, which is essentially that kind of hard mineral formed when calcium and phosphorus interact together. But it also has some other roles beyond just part of our bones and teeth. Phosphorus regulates protein activity through phosphorylation. So phosphorylation is essentially just adding a phosphorus molecule to a protein. In contrast, you can also remove a phosphorus molecule from a protein. And that whether, you know, whether the phosphorus is there or whether it's gone regulates how that protein functions. And so for some proteins, you can make them work more by adding that phosphorus. Other proteins, by removing that phosphorus, you're going to make it up. be more active. And so that is important for a ton of the chemical reactions in our body, whether a particular protein has been phosphorylated or not. Additionally, phosphorus is part of the phospholipids of our cell membranes. As we talked about in the lipids chapter, our phospholipids are those lipids that have that head that has a phosphate on it, and that phosphate contains phosphorus. On the other side, you have that tail that has the two fatty acids, and those orient in comparison with each other into that phospholipid bilayer that is what makes our cell membranes able to kind of enclose the inside of a cell. Phosphorus is also important for energy. So one of the kind of key currencies of energy in the body is what's called ATP and the P on there is phosphorus. And so, um, a lot of the chemical reactions in our body that needs to be powered, um, by, by, uh, chemical energy are going to have phosphorus as part of that. Phosphorus is also part of DNA. Um, similar to with proteins, how we have phosphorylation of proteins. that may make them more or less active. You can also phosphorylate DNA, which can turn genes on or off. And then additionally, phosphorus salts are buffers in our blood. They help regulate the pH of the blood, which as we've talked about, needs to be kept in a fairly narrow range. So phosphorus is found in a pretty wide variety of foods, especially foods that are going to be higher in protein tend to have more phosphorus. So if we look at kind of our animal-based foods, things like fish, chicken, pork, etc. Additionally, our plant-based sources of protein too are going to be relatively high in phosphorus. Things like beans, here they have trail mix, and that would be the nuts in the trail mix that are providing a pretty relatively high amount of phosphorus. We also have phosphorus in dairy products too. So all dairy products are going to provide a decent source of phosphorus, but you can also find them in other grain products. Additionally, soda will contain a decent amount of phosphorus that is... Part of kind of one of the additives that you'll find in certain types of soda is going to be pretty high in phosphorus. But phosphorus is found pretty widely in foods. So it's pretty easy to be able to get enough phosphorus. There is an upper limit for phosphorus, three to four grams a day, which is pretty high, as you'll see, compared to some of our other nutrients. It's toxicity is... not typically a concern for kind of a average healthy person, but it can be a problem for people who have certain types of kidney disease. Your kidneys help regulate the amount of phosphorus in the body. And so if your kidneys aren't working very well, it can be challenging for them to be able to properly regulate them. So people who have a severe kidney disease may be on what's called dialysis, where their kidneys aren't working properly to filter their blood. So instead, they rely on a machine that their blood goes through, and that machine more or less acts like a kidney being able to filter out the things that should be leaving the body. And then that kind of filtered blood will end up getting put back into the body. So people on dialysis need to limit their phosphorus intake because, as we know, in the bones, calcium and phosphorus can combine and make a hard, solid mineral compound. So in people with severe kidney disease whose kidneys aren't properly filtering out calcium and phosphorus, You can get these to combine together and precipitate, meaning forming a hard solid, and that can happen on the soft tissues of the body. So like our muscles, organs, and blood vessels, which we definitely do not want hard mineral solids on those parts of the body. So this is something that they really closely monitor for people on dialysis. Uh, people on dialysis are asked to limit their phosphorus intake, but that is... pretty challenging since it's so widely found in foods that people with dialysis can actually take what's called phosphate binders. So it's a kind of chewable pill that they'll take with their food and that will help bind the phosphorus and it'll just be excreted in the feces. At least a portion of it will be excreted in the feces and will limit the amount that the body absorbs in an attempt to try to limit the amount of calcium phosphorus precipitate that can be happening inside the body. Next, we'll talk about sodium. So we tend to think of sodium in a negative light because we know too much sodium is not good for us. However, sodium is an essential nutrient. We do need it to stay alive. So sodium is an electrolyte and it is really important. in maintaining fluid and electrolyte balance. So we need the proper concentrations of sodium in the proper parts of our body. Sodium is the principal positive ion outside the body cells, as we can see in this picture. So we see a cell membrane and then we see what's outside of that cell. And we see that we have a lot of sodium outside the cell, just a little bit of sodium inside. And then kind of on the opposite side, we have a lot of potassium inside the cell and not a lot outside. And so they kind of work together to maintain the appropriate amount of fluid in the appropriate places. And so sodium helps maintain the proper amount of fluid outside of the cell. Sodium is also important in acid-base balance, maintaining pH, as well as muscle contraction and nerve transmission. So we know that sodium is related to increased blood pressure. So this slide explains why that happens. So as we've talked about before, electrolytes and fluid are really tightly linked. And so essentially, that's why sodium is related to. blood pressure. So when you eat more sodium, you are going to have more sodium in the bloodstream. And so as we know, we need to keep the concentrations of certain electrolytes within a certain range. And we also know that water is going to flow to the place of higher concentration of electrolytes. So water is going to follow sodium. And that means that we are going to have an increased amount of water in our blood vessels. And so we are going to have more blood in our blood vessels, but our blood vessels can only change size so much. They can't just kind of unlimitedly expand in order to, you know, take up that extra water. So because our blood vessels aren't going to be able to expand enough to accommodate this extra water. it's going to increase the pressure in our blood vessels. We see that here on this image where we see our blood vessels staying the same size, but we have a higher volume of fluid that's flowing through these vessels. And so that's going to increase the pressure. The recommendations for sodium are actually not a minimum recommendation generally that we think of, but are actually an upper limit. So for the average person, it's recommended to consume less than 2,300 milligrams of sodium per day. However, for people who have hypertension or pre-hypertension, kind of elevated... elevated blood pressure, but not to the point of actually having hypertension, these people are recommended to limit their sodium quite a bit more to 1500 milligrams of sodium per day. So the upper limit for sodium is 2300 milligrams per day for adults, unless they have hypertension or pre-hypertension. Sodium is one of those things that is vastly over consumed in the US. So here we see the average consumption in males and females compared to the adequate intake, which the 1500 milligrams seems to be enough for most people. Most people shouldn't need to consume more than that. 2300 milligrams is the upper limit. And then we have in orange, the average consumption of sodium in the US. So we see for males it's over 4,000 milligrams a day which is quite a bit more than the 2,300 milligram upper limit. For females it's about 3,000 milligrams a day, still quite a bit more than the 2,300 milligram upper limit. So sodium in our food comes from a variety of sources. So first let's start on the left with unprocessed foods. So this is just the sodium that is naturally occurring in food, you know, as we might get it from nature. So things like fruits, vegetables, meats, eggs, dairy, etc. Most foods are going to have a very small amount of sodium naturally occurring. So when you pull a potato out of the ground, when you get milk from a cow, there's going to be some sodium in it already. And so we can't remove any of this anymore. It's just there. So these unprocessed foods overall contribute on average less than 10% of the sodium in the U.S. diet. And so we can see the amount of milligrams here. And once we compare it to the ones all the way to the right, we'll see that it's a huge, huge difference in the amount of sodium that's naturally occurring in foods. Versus what we might get in processed foods. But there is a small amount that is naturally occurring in foods. About 15% of the salt that is consumed by the average American is added in cooking. So either while you're preparing your food or at that table where you are actually using the salt shaker. So we see here that one teaspoon of salt, you know, from the salt canister is going to provide us with 2,300 milligrams of sodium. So one teaspoon of salt, um, is the upper limit for the day. Um, so that will just kind of help you keep in mind, uh, kind of what it might look like of pure salt to meet the, uh, the upper limit. When you're looking at a salt shaker, it has about 100 milligrams per shake. Obviously, that'll vary a bit by what type of salt shaker you have, but that's what we can think of about on average. And again, about 15% of the sodium consumed in the US is either added while you're cooking your meal or at the table. But 75%, the vast majority... is actually found in processed or packaged foods. So it's already in there by the time you bring it home. So this is where generally we tell people who would like to reduce their sodium intake to try to watch out for. So either reducing processed packaged foods overall or trying to find those that are lower in sodium. So there are going to be some that are just kind of always really high in sodium. So things like pickles, um, here we have ham, uh, things like fast food, uh, frozen meals, box macaroni and cheese, et cetera. All of those tend to be really, really high in sodium, um, and are generally recommended to limit on a diet. reduce sodium diet. Here we also have some canned vegetables. That is one where you can actually find lower sodium versions. So that would be one that I wouldn't say just to totally get rid of. That would be one to watch out for, which we'll talk about more in a minute. So kind of the general relationship between sodium content in food and the degree of processing. is that the more you process a food, the more you increase the sodium content. So generally foods, you know, as you find them in nature are going to be relatively low in sodium. So here we have just, you know, plain rice doesn't have any sodium. An apple may not have any sodium. Vegetable oil may not have any sodium, but a couple of these other things do have some amount of sodium naturally occurring. Um, milk is actually one of the foods that, you know, unprocessed foods that tends to be a bit higher in sodium, but still relative to as we, you know, ramp up the processing up fairly low. But we see once we get into this kind of middle category, um, so something like a boxed rice pilaf, like rice or roni, you're increasing that up to 580 milligrams. Um, if you buy French fries, those have generally had sodium added. Um, margarine is going to have more sodium than oil. Cheese is going to have more sodium than milk. A, you know, more processed meat product like chicken nuggets is going to have more sodium. But if you go, you know, all the way to the right, you'll see kind of the, the foods that we buy that are, you know, kind of ready to eat. Um, those tend to be really high in sodium. Um, so something like a bottled salad dressing, um, a, you know, canned soup. Deli meat. Those are all foods that are really really high in sodium. So here we see How much sodium is in a variety of foods again? one teaspoon of pure salt is going to pretty much provide the upper limit of sodium for a day Some of those things that are you know, especially high in sodium are going to be pickles canned soups processed meats or deli meats. Cottage cheese is one of those foods that's otherwise really healthy, but it does have a lot of sodium in it. So that's kind of the downfall of cottage cheese. But whenever you are buying kind of like canned, boxed, frozen things, those tend to be pretty high in sodium. So if you were to get some... canned tomato juice or jarred marinara sauce. Those do tend to have quite a bit of sodium added. However, there are more products on the market now that are either no salt added or reduced sodium. So always just watch out when you're at the store looking at labels and trying to find the lower sodium versions of the things you like. The upper limit of 1500 milligrams, that lower recommendation is generally put in place for people who are at higher risk of hypertension or high blood pressure. So people over 50 tend to be at higher risk of high blood pressure. People of African American or African ethnicity tend to be at higher risk of high blood pressure than other races or ethnicities. People who already have high blood pressure, people with diabetes, and people with kidney disease are all recommended to go with that lower level of sodium. So how to reduce your sodium intake. So this is something that virtually anyone you meet is going to exceed the recommended amount of sodium. So this advice applies to pretty much anyone. So one way is to go out to eat less. Foods that you get going out to eat are... almost always going to be really high in sodium. If you were to, you know, go to a salad bar and you were able to, you know, pick out all your vegetables and if they happen to have a... low sodium dressing. Like that would be one way that you might be able to reduce your sodium intake while going out to eat. But almost anything you get going out to eat is unfortunately going to be really high in sodium. Cooking more from minimally processed ingredients is going to allow you to control what you're putting into your meals and is going to allow you to start with things that are really low in sodium. However, a lot of us don't have the time to cook all of our foods from scratch. So it is still really important to try to find the lowest sodium choices out of packaged foods. So when you are buying packaged foods, whether it's something that's still relatively minimally processed, like canned beans or canned vegetables, or if it's something like a soup that's ready to eat that is more processed, Um, look for those that have lower sodium. So you can look for things that are reduced sodium or no added. And so, um, some of the really healthy choices, um, that are, you know, canned or frozen, um, things like canned beans, you can find reduced sodium or no salt added. Uh, same thing with other, other canned vegetables like canned tomatoes and, uh, you know, canned green beans, et cetera. Um, One thing to point out though, is that there are some foods that say reduced sodium, but they're still really high in sodium. One thing that fits this bill is soy sauce. That is one thing that is just extremely high in sodium. So even if you were to get a reduced sodium soy sauce, it is still going to be high in sodium. It's just going to be lower in sodium than the kind of regular. version of it. So you'll still want to, if you are trying to watch your sodium intake, you'll still want to watch how much soy sauce you're using. One of the things you may find if you are trying to reduce the sodium in your diet is that food is going to start to taste pretty bland if you do that. One of the things to try to make your food not taste so bland while you're reducing your sodium is to reduce the sodium in your diet gradually. Don't just, you know, all of a sudden try to go to a no salt added diet. If you reduce gradually, your taste buds will start to adapt to less sodium. And you'll, you know, over time, you'll get to a point where if you were to eat something that may taste fine to you right now, after you've gotten accustomed to less sodium, that will actually taste way too salty. So you do start to get used to it and you can certainly do other things to try to make your food less bland too. At the same time, citrus or other acidic things like vinegar can be a good way to make your food have more flavor while you are reducing your sodium intake. But also things like herbs and spices will certainly help there too. So some of the packaged foods to watch out for that are highest in sodium are listed here. This is certainly not all of them, but some of those that are higher, that are especially high. So a lot of our frozen meals are going to be really high in sodium. But just if this is something that you really rely on because you're too busy or you just, you know, aren't, you know. super skilled at cooking. Frozen meals can be a healthy choice. Obviously, they are not all made the same. Some are, you know, have whole grains and vegetables while others don't. Look for frozen meals with lower sodium if you are, if that is something that's really important to you. But kind of the average frozen meals tend to be really, really high in sodium. Frozen vegetables, um if you are getting just a plain frozen vegetable that doesn't have any salt or seasonings or any sauce or seasoning those are typically going to be no salt added but if there is a frozen vegetable that might have a cheese sauce or something like that um those may have a lot of sodium added um but always just look at your labels to see um different brands different flavors are going to have different amounts of salt added to them canned soups and broths like vegetable broth chicken broth beef broth um all tend to be really high in sodium um but certainly there are more products on the market now that are going to be lower in sodium um some even have uh no salt added uh deli meat and processed meats uh things like bacon ham sausage these are some that are pretty much always going to be really high in sodium. They don't, at least to my knowledge, have lower sodium options available at this point. Canned vegetables and beans, these kind of standard versions that you get are going to tend to be pretty high in sodium, but obviously vegetables and beans are healthy foods. Canned choices can be cheaper, more convenient. uh, they, they don't go bad. And so you don't need to worry about, um, you know, just keeping some on hand. You can always have those ready for you. Um, if you don't have any fresh or frozen vegetables around. So these can be really good choices. Um, but the sodium content can be pretty high. Uh, again, you can always look for, uh, no salt added or lower sodium versions, but if you can't find those easily, um, if you drain and rinse, uh the regular versions of these um that will remove um a good portion of the sodium so some of the sodium is going to be kind of absorbed into the vegetable or the bean and that you can't remove but some of them um uh some you will get rid of a good deal of the sodium if you drain in from them condiments and sauces are another category of foods that tends to be really really high in sodium um Things like ketchup, stir-fry sauces, soy sauces, you may be able to find lower sodium versions, but something like soy sauce, even a lower sodium version is still going to be really high in salt. Salad dressings that are, you know, bottled do vary quite a bit. Some are going to be super, super high in sodium. Others are actually really low in sodium. So again, it's all going to be down to kind of looking at those labels to see. If you can find a low sodium version, uh, snacks like chips, uh, pretzels, uh, goldfish crackers, things like that, uh, tend to be really high in sodium. Um, breads are another one that we don't think of as tasting salty, but they do have a fair amount of, of salt in them. Um, so this is things like, uh, sliced bread, loaves of bread, um, buns, et cetera. Those all tend to have a decent amount of sodium in them. And especially if you're someone who might eat toast for breakfast, a sandwich for lunch, and maybe some bread with dinner too. That will definitely add up over the day. And then lastly, we have our brined foods. All of these are going to be really, really high in salt. And there generally aren't a lot of low sodium options here for things like pickles, olives, and corned beef. So while it's really, really rare to not get enough sodium, there is a possibility to get sodium deficiency, which we talked about in the water section. So this is called hyponatremia. And this is where typically we don't think of it as just a dietary deficiency. This is going to be something that happens with athletes who are doing um, really intense endurance activity. So something like a marathon or an ultra marathon. And so hyponatremia means low sodium in the blood. So what's happening with someone who's doing a really intensive, long endurance activity is they are sweating a lot. So they are getting rid of a lot of electrolytes like sodium. And they're also drinking a lot of fluids and so that is going to be diluting the sodium in their body so especially if they are just drinking water and they're not drinking a sports drink or something else that is going to provide them with electrolytes um they could end up having low sodium in their blood um as we talked about that this can um be fatal this um this can be really serious you And so this is one reason why it's really important for people doing those really intensive endurance activities like marathons to have something with electrolytes, whether it's a sports drink or a tablet that has electrolytes when they're doing their activity instead of just water. So next we will talk about potassium. So this is... Pretty closely related to sodium in the body. So potassium is the principal positive ion inside the cells, and it maintains the appropriate amount of fluid inside the cell. So sodium and potassium work kind of together on things like fluid balance, nerve impulses, and contracting muscles, including your heart. And so if you have taken biology classes before, you may have heard of the sodium potassium pump. And so that is a transport protein that goes through the membranes of cells that is going to be responsible for transporting both sodium and potassium. And so they're tightly related in the body. Potassium can also be used to reduce some of the effects of sodium in the body. So if someone is eating a lot of potassium, that may reduce the amount that sodium is able to reduce the... I'm sorry. If you have a lot of potassium intake, sodium is not going to impact your blood pressure as much. So high potassium intake promotes getting rid of extra sodium. Um, so you're not going to keep as much sodium in the body. Uh, you're going to excrete it through your urine and it is going to reduce the, uh, amount that excess sodium is able to impact your blood pressure. And so we know that potassium intake is associated with lower blood pressure. Uh, potassium is found in highest amounts in, um, our whole plant-based foods. So things like fruits and vegetables, uh, beans, but also is found in, uh, pretty high quantities in dairy. Um, so if you eat a, um, a variety of fruits and vegetables, you will be getting, um, a good source of potassium. We always think of bananas as being one of the highest potassium foods, but if we look at this graph, we see that there are also several other fruits and vegetables that are really good sources. So potatoes are actually an excellent source of potassium. One medium potato with skin will provide us with about 30% of our daily potassium. Beans... are a great source of potassium but also things like orange juice tomato sauce and broccoli too the recommendation for potassium is 4 700 milligrams per day quite a bit and most people do not come anywhere near that we know that people eat far less than the recommended amount of fruits vegetables um and legumes. And so that contributes to the low potassium intake in the U.S. Potassium deficiency is really rare. It's generally not something that happens from diet. Our body's really good at regulating potassium in the body. So it is not generally going to be from a dietary deficiency that you would end up with low potassium in your blood, which is called hypokalemia. but it can happen with, um, some other medical conditions. It is a life-threatening condition. Um, it can cause weakness, fatigue, irregular heartbeat, and, um, eventually death. Um, but again, it's generally not going to be from, um, anything related to the diet. Uh, so people who might be at risk of a potassium deficiency in the blood, um, include people who are on it. certain drugs to treat hypertension. So sometimes diuretics, which are medications that are going to cause you to excrete more fluid, basically you are going to urinate more, getting rid of more fluid. That'll also get rid of some of the electrolytes in your body too. And these are sometimes used to treat hypertension or high blood pressure. Certain diuretics are going to deplete potassium in your bloodstream. And so doctors will usually monitor this and also sometimes give people a potassium supplement in addition to their diuretic in order to prevent this from happening. But people with eating disorders who are doing things like vomiting or laxatives, These can really throw off your fluid and electrolyte balance, which can put people at risk for life-threatening issues related to fluid and electrolyte imbalances, including potassium. Potassium toxicity can also occur, and when you have high potassium in the blood, this is called hyperkalemia, which is also life-threatening. Again, this generally is not going to happen due to diet. Healthy people are able to regulate excess potassium and are able to just get rid of it. However, people with heart conditions, people who take incredibly high dose supplements or infants who may not be as good at regulating potassium in the body, this can be a life-threatening condition. So we will talk about the DASH diet later in the semester, but I wanted to just really quickly bring it up while we are talking about sodium and potassium. So the dietary approaches to stop hypertension diet is a diet that is specifically formulated to reduce high blood pressure. And so one of the kind of cornerstones of this diet is that it's high in potassium, but low in sodium. And so it's, um, an effort to try to, um, use those electrolytes to your favor to, um, reduce blood pressure. And so it's really, really heavily focused on, um, foods that are high in potassium, like fruits and vegetables, low fat dairy, um, and low in sodium. So magnesium is also another mineral that is really important in our bones. So 60% of the magnesium in our body is stored in our bones. The rest is in our muscles and some other tissues. Magnesium is one of those minerals that is really important to serve as a cofactor for enzymes. As we talked about, cofactors are those things that are beyond the protein. that are needed for that protein to have its enzymatic function. It kind of will fit into that protein. It will get added later after that, you know, all the amino acids have been added after, you know, the protein has been freed from the ribosome. A magnesium molecule will get added to some proteins and that will cause that enzyme to be able to... do the chemical reactions it needs to do. So magnesium is used for a ton of different enzymes in the body. Some of those enzymes are part of energy metabolism. And magnesium is also important for muscle and nerve function. Deficiency of magnesium is very, very rare, especially from the diet. It's something that we don't really see, but deficiency can cause muscle cramps. and seizures. Magnesium deficiency in the body can happen with certain medications and also with alcohol use disorder. Magnesium is found in a variety of foods, but especially things like nuts, green leafy vegetables, beans, milk, and whole grains. Toxicity is not really something we worry about. Like with most, most of them would nutrients we talked about, except from high intake from supplements. Now we'll move on to the trace minerals. So these are the minerals that are needed in quantities less than 100 milligrams per day, whereas everything we've already talked about are things that we need in greater quantities than that. So we have the list of the trace minerals here. We're only going to talk about three in detail. iron, zinc, and iodine. So iron, as we've talked about a bit already, iron is really important for oxygen transport in the body. Iron is part of hemoglobin in red blood cells. So here we see on the left a picture of the hemoglobin protein. And we use this as an example in the protein chapter of a protein that has several different subunits, which we see here in the two red subunits and the two purple subunits all coming together to form the full hemoglobin molecule. So in each of the subunits, you have what is called heme. And that is this kind of bigger picture we see here. So heme is a molecule. That is going to have an iron at the center, which is what we see here with this FE. So that is how we show iron on the periodic table is with FE. So each one of these separate subunits is going to have an iron in it. And that iron is going to be able to bond with oxygen and transport oxygen throughout our body on the red blood cells. We also have a similar protein in our muscles called myoglobin, which we see on the top right. It's just a single subunit. It's pretty similar to the single subunits of hemoglobin. It also is going to be able to transport oxygen, but it is only found in our muscle cells. In addition to oxygen transport, iron is involved in several other processes in the body. including as part of enzymes used in energy metabolism. It's also important for the synthesis of neurotransmitters, which is important for brain development. And it's also needed for production of immune cells. So iron in food is found in two different forms. So as we just talked about, the form of iron that is found in hemoglobin and myoglobin is called heme iron. And here we see kind of a more chemical structure of what the heme molecule looks like. And then at the center of it, we have iron. And so this is what we call heme iron, is iron that is found as part of the part of this heme molecule. So heme iron is found in hemoglobin and myoglobin and thus is only going to be found in animal flesh foods. So things like beef, chicken, fish, pork, those types of foods are going to have heme iron. You're not going to find heme iron in things like eggs or in any plant based foods. Heme iron is the most bioavailable form, meaning that we are able to absorb it the best when compared with non-heme iron. So non-heme iron is not part of this heme molecule. So it's the type of iron that is all of the iron found in plants. So things like beans and grains, all of the iron in those types of foods are going to be heme iron. And And then all of the iron in eggs is also non-heme iron. So animal flesh foods, though, however, have a mixture of both heme iron and non-heme iron, as we see in this top right picture. So in our animal flesh foods, which is meat, fish, and poultry, 60% of the iron is non-heme iron. Whereas for... 40% of the iron in it is heme iron. So in contrast, our plant-based foods, again, things like beans and grains, as well as eggs, all of that iron is non-heme iron. And that non-heme iron is not as bioavailable, meaning that we do not absorb it as well. So iron in foods is found in high amounts in beef. So red meat is actually the animal-based, animal-fleshed food other than a few particular types of seafood. There's more iron in beef than there is in chicken and poultry. However, there are kind of a couple seafood sources of iron that are really high. So things like clams. Those have a ton of iron in them. When we are talking about our plant-based sources, those that tend to be the highest are beans, certain leafy green vegetables. Some grains have a decent amount of iron, but then you'll also find a lot of foods that are fortified with iron, meaning that they have iron added. So something like life cereal or Wheaties may have quite a bit of iron added to it. So while the last slide, we looked at just like the pure quantity of iron in food, remember that it is going to not all be absorbed the same. So not all iron from food, you're not just going to want to pay attention to the amount of iron that the food label says is in there. You also need to pay attention to how well that it... it is absorbed by the body. And again, this is what we call iron bioavailability. Um, iron is one of the, the more complex things in the body with regards to bioavailability. So there are a lot of things that, um, may increase absorption, a lot of things that may decrease absorption. Um, so, uh, iron status in the body, um, is basically how much iron you have in your body. Do you have enough? Are you what we call sufficient or do you not have enough? That's what we would call deficient. So if you are deficient, you are actually going to increase absorption. It's your body trying to make sure that you are getting enough. So you are going to absorb more iron from a food. It's going to be more bioavailable if you are deficient. Um, also if you are someone who... has a high need for iron, you will tend to absorb more as well. So anyone who is undergoing blood loss, so this could be just people going through menstruation. It could also be someone who, you know, potentially they got a cut, you know, a wound where they lost a lot of blood or someone who is having a, you know, chronic. bleed from their gastrointestinal tract, which we actually do see quite frequently. So anyone who's losing blood for whatever reason has a higher need for red blood cells. And so they're going to be able to absorb iron better from their food. But some other things are also going to increase the need for iron. So people who are living at high altitude, actually, because there's less oxygen in the air, they're going to need more red blood cells to be able to transport oxygen throughout their body. So people living at high altitudes are able to absorb iron a bit better. People doing really intense physical exercise like elite athletes may have higher iron needs. Pregnancy certainly increases iron needs. And if you have iron deficiency anemia, if you are actually deficient in iron, you are going to absorb iron better. Um, similarly, if you have low body stores of iron, so iron is something that we store in our liver. If we don't have very much there, our body is also going to try to, uh, make sure that we have enough and increase our absorption of iron. Um, on the other hand, um, if you have plenty of iron in your body, if you have a high, high amount of iron stores in your liver, you you don't need as much and so you are going to not absorb as much so your body does a decent job by trying to kind of protect you as much as possible from either too little iron or too much iron um so heme iron in food again is going to be that iron that is solely found in animal flesh foods but only makes up a portion of that iron um that is absorbed much, much easier than our non-heme iron. And also that heme iron is not going to be impacted by these other things in these black boxes. So heme iron absorption or bioavailability is not impacted by things like vitamin C, polyphenols, et cetera. So all of these things in these black boxes are factors that only impact non-heme iron absorption. So it's that non-heme iron that the amount that we absorb is highly impacted by all of these other things. So if you are eating vitamin C at the same time as you're eating something with non-heme iron, you will actually absorb more of it. If you're also eating a source of non-heme iron like... beans or whole grains, if you are eating that at the same time as something as either meat, fish, or poultry, which we call the meat, fish, poultry factor, if you eat plant-based sources of iron at the same time as you're eating meat, fish, and poultry, you're actually going to absorb more of that non-heme iron, which is really interesting. However, kind of on the decreasing absorption side, we have a ton of different things that will actually reduce our ability to absorb iron, which some people don't need to worry about. Other people though, who may have iron deficiency or be at risk of iron deficiency will want to pay attention to these things. So phytic acid is a compound found in certain plant-based foods. So whole grains and legumes. It's not something that's actually unhealthy for us. But for people who need to really pay attention to making sure they're getting enough iron absorbed into their body, it's something that they need to think about. So whole grains and legumes have something that will actually decrease absorption of iron. Oxalic acid or oxalates is another compound found in some plants, particularly some green leafy vegetables, spinach and Swiss chard in particular. are especially high in oxalates. So while you may see that spinach is considered a decent source of iron, not much of that is actually absorbed. So if you are someone who may be a vegetarian or a vegan, there are definitely better foods that should be considered as sources of iron other than spinach and Swiss chard. Polyphenols, again, are one of these phytochemicals. Classes of phytochemicals. So they are health promoting foods. They are health promoting compounds. They are good for us. However, they do decrease iron absorption. And so polyphenols are found in tea, coffee, red wine, and a bunch of other foods. If you have reduced gastric acidity, so people with various health conditions may not produce as much stomach acid. And so if you produce less stomach acid, you don't absorb iron as well. And then lastly, if you have excessive intake of other minerals like zinc, manganese, or calcium, that can reduce the amount of iron you're absorbing. As we talked about a few times this semester, some things compete for absorption in our small intestine. So certain minerals are going to absorb through the same places. And so if you have a ton of one, it's going to reduce the amount of iron you're absorbing. reduce the amount that you absorb of another. So if you are someone who is at risk of iron deficiency or you do know that you are iron deficient, this could be someone who's a, you know, for example, vegan, vegetarian, or, you know, for whatever other reason that you are iron deficient, here are some ways that you can try to increase your absorption of iron. Eating vitamin C rich foods with sources of iron. So if you, um, are eating something like, uh, you know, strawberries, bell peppers, orange juice. Um, if you have that at the same time that you're eating a source of iron, like, uh, uh, beans, um, whole grains that can help you absorb more of the iron from those foods. Uh, don't drink coffee or tea with meals because those have those polyphenols that reduce iron bioavailability. Uh, don't take other mineral supplements at the same time as iron supplements. So for example, if you need an iron supplement, don't also take a calcium supplement at the same time that will decrease the amount of iron you will absorb from the calcium. Also just a note, you don't need a supplement unless you are deficient. Um, there are plenty of people who may be on a vegan or vegetarian diet who, um, for whatever reason, uh, they... are not iron deficient, they're doing just fine. So if you're in that boat, then even if you're a vegan or vegetarian, you don't need a supplement. However, if you are a vegan or vegetarian and you are iron deficient and take a supplement, then don't take it at the same time as other mineral supplements you might take. So wanting to absorb more iron, this isn't something that everyone needs to do. Only people who... may be at risk of iron deficiency need to really focus on this. Um, so, um, biological females of childbearing age. And so essentially we are talking about people who are having a menstrual period. Um, those are the people who have the highest iron needs, um, because you are needing, you're, you're losing iron every month. Um, so when we look at the RDA for iron, we'll, we'll see that it's much, much higher. for biological females of those menstruating years. Additionally, during pregnancy, iron needs are really elevated as well. And so iron deficiency during pregnancy is fairly common too. So iron deficiency is the most widespread mineral deficiency worldwide. And it's one of the few deficiencies that we actually do see. pretty commonly in the U.S. And so the deficiency disease we see with iron deficiency is called iron deficiency anemia. It's where you have low hemoglobin in your blood. So with iron deficiency anemia, you'll see fatigue. So basically you'll be tired. It's difficulty to get through your daily activities because you just get really tired. It can also negatively impact the immune system as well. Iron deficiency is particularly of concern for children because it's important for cognitive or brain development. And so, iron deficiency during young children can end up with cognitive or developmental impairment. So people who are at risk of iron deficiency, it's a pretty wide amount of people. So those who have low dietary diversity, which we've talked about with especially low income, more developing countries where people rely really heavily on a few staple crops. So these people are going to tend to be eating a lot of just baby rice. um, cassava, uh, corn, something like that, that is, um, not a great source of iron. Um, they're not eating many, uh, animal flesh foods. And so they're not getting a great source of iron in the diet. Um, so that's why iron deficiency is one of the, uh, most serious deficiencies worldwide. Um, but outside of that, um, these other, uh, categories of people, um, we will find in the U.S., so you may see iron deficiency among these groups of people. Premature infants are born before iron has been transferred to the fetus, and so most of the iron transfer actually happens late in pregnancy. So if they're born before that happens, they are going to be born pretty deficient in iron. Iron deficiency can be more common among young children during pregnancy. vegetarians, vegans, as we talked about. Again, biological females of childbearing age, people during the menstruating years. Iron deficiency becomes pretty rare after menopause though. So after people have stopped having menstrual periods, iron needs go down and iron deficiency becomes pretty uncommon. People who have especially heavy menstrual periods are at increased risk of iron deficiency, again, because they have a higher need for red blood cells because they are losing red blood cells very frequently. Any other kind of condition where you are going to be losing blood is also going to put you at risk of iron deficiency. So people who donate blood frequently may be at risk of iron deficiency. And also, One of the more common causes of blood loss we have is from a GI bleed. So it could be in the stomach, it could be in the intestines, but there are various conditions that will cause people to have bleeds. Often not really severe acute losses of blood at one time. It might be kind of a slow bleed over a longer period of time. That can cause people to become iron deficient as well. And so iron deficiency is measured by your hemoglobin in your blood. This is one of the really, really common blood tests. So if you get, you know, annual blood tests, this is probably something that you're going to get measured. And so your doctor should tell you if one of these kind of routine tests show that you are iron deficient. Iron toxicity is also a concern. It is one of the most toxic micronutrients. So it is one of the most common to also have accidental overdoses. So iron pills are often red, like you see here, and they can, especially to children, look like candy. And so there are certainly instances where children may, you know, stumble upon a bottle of iron pills and take a whole bunch thinking they're candy. And so it is the most common poisoning in children and it can be fatal. So it's really important to make sure that you keep supplements containing iron out of reach of children. There is also a condition called hereditary hemochromatosis. And so this is a genetic condition where people are going to absorb kind of an abnormally high amount of iron. Their body is not going to normally, if you don't have this condition, your body prevents you from absorbing too much iron because excess iron is very toxic in the body. However, people with this condition, their body... doesn't kind of turn that off. You just always absorb a really high amount of iron. So people with this condition may need to reduce the amount of iron they get from their diet. But then also the way this is treated is just blood donation. So essentially just taking out those red blood cells periodically, forcing your body to use up more iron to replace them is actually a very effective treatment for this condition. So signs and symptoms of toxicity of iron include bloody vomit and or diarrhea, organ damage, and this is certainly a fetal mineral toxicity if it is severe and untreated. Zinc is another one of those minerals that is used as a cofactor for enzymes. It's used in 300 enzymes in the body and participates in thousands of chemical reactions. It is especially important to create DNA and RNA. It is an antioxidant in the body, meaning that it will kind of... prevent those free radicals that we talked about in the vitamins chapter. It can help prevent those free radicals from damaging the body. And it's also essential for producing that hemoglobin molecule that is going to get put into the hemoglobin protein. So zinc is found in really high amounts. in seafood, but also in red meat. So people who are eating, um, animals are generally going to have ample amounts of zinc. Um, it's also found in things like nuts, legumes, and whole grains. Um, so vegetarians and vegans also are able to get sources of zinc as well. Um, plant-based sources are not as well absorbed though, kind of similar to what we saw with iron. Um, But it's not as much of a nutrient of concern for vegetarians and vegans, in the US at least, as we are concerned about with iron. So zinc deficiency outside of the US though is one of the more prevalent nutrient deficiencies worldwide. So again, especially in developing countries who are not eating much animal flesh foods, so people- may not be eating much meat, fish, or poultry, and may also not be having much milk. Zinc deficiency can cause what is called stunting. So as we see in this picture here, this youth is only about four feet tall at 17 years old. And so zinc deficiency can cause what's called stunting or stunted growth. zinc deficiency also negatively impacts the immune function and it can cause diarrhea, which is, um, as we talked about, um, earlier in the semester, there's that, uh, kind of cycle of malnutrition and, um, infectious disease that they just make each other worse. And so zinc deficiency, um, can, uh, end up, um, with putting people, especially young children at risk of severe diseases that would normally not. be very, uh, very harmful to the body. But, um, when you have this cycle of malnutrition and infectious disease, diarrhea, um, they can end up being fatal. Uh, so zinc toxicity can occur with really high supplemental intake and can cause vomiting, diarrhea, and headache. Now we will move on to iodine. So iodine is a mineral that is needed for your thyroid hormone. Your thyroid is a gland that is located in the throat region. And it produces several hormones for the body. And as we've talked about throughout the semester, hormones are really important for regulating body functions. So thyroid hormone regulates what's called your basal metabolic rate. So essentially kind of how many calories you're burning at rest. So when you're not doing much, most of your calories are still from, you know, just those basic things that your body needs to do to keep you alive. So it regulates your basal metabolic rate. It regulates the body's temperature and is also really important for growth among children. So iodine is not found in a lot of foods. Naturally, it is found in highest amounts in things like dairy and things that come from the sea because iodine is really high in salt water. So seafood will provide iodine. Seaweed has really high amounts of iodine. But a lot of the iodine in the U.S. is going to come from iodized salt. So it's mandated that kind of normal salt, not sea salt, but kind of your typical salt, is going to contain iodine in the U.S. And so it's fortified. It has been added to it. And so a teaspoon of iodized salt is going to provide several times the RDA for iodine in the U.S. And is one of the more common. sources of iodine in the US. Iodine deficiency is not common in the U.S., but it is one of those common deficiencies worldwide. So here we see a graph of where there is the most severe iodine deficiencies worldwide. So iodine deficiency can cause what's called... goiter, which we see in this woman, um, with the lump in the, uh, the, the neck. Um, and so you have your thyroid gland, um, becoming bigger and bigger and bigger until it becomes quite visible, um, that it has gotten larger. And so what's happening here is when you don't have enough iodine, there's a, uh, hormone that's released called TSH, uh, thyroid simulating hormone. That is going to stimulate your thyroid to get larger in an attempt to try to trap more iodine. And if you don't have much iodine in your body, it's just going to keep getting bigger and bigger and bigger in an attempt to get more iodine. But if there's just not any iodine there, it's not going to be able to do that. So there are... several symptoms of iodine deficiency, uh, slowed metabolism, um, meaning you're burning fewer calories. So you will, um, often see weight gain, um, happening with iodine deficiency, um, because of iodine's role in temperature regulation, uh, people with iodine deficiency will also feel cold and then it can also cause depression. Iodine deficiency, um, during iodine. Pregnancy can also have some serious impacts on the baby being born. So congenital iodine deficiency syndrome causes impaired fetal brain development and growth. So you will have intellectual disability, loss of hearing and speech, and also very short stature. Iodine toxicity is very rare, but It can occur from really excessive intake from supplements. Similar to iodine deficiency, you can see an enlarged thyroid and it can also be fatal.

This is part two of the minerals lecture. So we are going to continue on with the major minerals that are found in large amounts in the body. Next, talking about phosphorus.

So phosphorus is one of the most abundant minerals in the body, second only to calcium. The majority of the phosphorus in our body is found in bones and teeth. It combines with calcium to find to to make up this compound called hydroxyapatite, which is essentially that kind of hard mineral formed when calcium and phosphorus interact together. But it also has some other roles beyond just part of our bones and teeth. Phosphorus regulates protein activity through phosphorylation.

So phosphorylation is essentially just adding a phosphorus molecule to a protein. In contrast, you can also remove a phosphorus molecule from a protein. And that whether, you know, whether the phosphorus is there or whether it's gone regulates how that protein functions. And so for some proteins, you can make them work more by adding that phosphorus. Other proteins, by removing that phosphorus, you're going to make it up.

be more active. And so that is important for a ton of the chemical reactions in our body, whether a particular protein has been phosphorylated or not. Additionally, phosphorus is part of the phospholipids of our cell membranes.

As we talked about in the lipids chapter, our phospholipids are those lipids that have that head that has a phosphate on it, and that phosphate contains phosphorus. On the other side, you have that tail that has the two fatty acids, and those orient in comparison with each other into that phospholipid bilayer that is what makes our cell membranes able to kind of enclose the inside of a cell. Phosphorus is also important for energy.

So one of the kind of key currencies of energy in the body is what's called ATP and the P on there is phosphorus. And so, um, a lot of the chemical reactions in our body that needs to be powered, um, by, by, uh, chemical energy are going to have phosphorus as part of that. Phosphorus is also part of DNA. Um, similar to with proteins, how we have phosphorylation of proteins. that may make them more or less active.

You can also phosphorylate DNA, which can turn genes on or off. And then additionally, phosphorus salts are buffers in our blood. They help regulate the pH of the blood, which as we've talked about, needs to be kept in a fairly narrow range.

So phosphorus is found in a pretty wide variety of foods, especially foods that are going to be higher in protein tend to have more phosphorus. So if we look at kind of our animal-based foods, things like fish, chicken, pork, etc. Additionally, our plant-based sources of protein too are going to be relatively high in phosphorus. Things like beans, here they have trail mix, and that would be the nuts in the trail mix that are providing a pretty relatively high amount of phosphorus.

We also have phosphorus in dairy products too. So all dairy products are going to provide a decent source of phosphorus, but you can also find them in other grain products. Additionally, soda will contain a decent amount of phosphorus that is...

Part of kind of one of the additives that you'll find in certain types of soda is going to be pretty high in phosphorus. But phosphorus is found pretty widely in foods. So it's pretty easy to be able to get enough phosphorus. There is an upper limit for phosphorus, three to four grams a day, which is pretty high, as you'll see, compared to some of our other nutrients.

It's toxicity is... not typically a concern for kind of a average healthy person, but it can be a problem for people who have certain types of kidney disease. Your kidneys help regulate the amount of phosphorus in the body. And so if your kidneys aren't working very well, it can be challenging for them to be able to properly regulate them.

So people who have a severe kidney disease may be on what's called dialysis, where their kidneys aren't working properly to filter their blood. So instead, they rely on a machine that their blood goes through, and that machine more or less acts like a kidney being able to filter out the things that should be leaving the body. And then that kind of filtered blood will end up getting put back into the body. So people on dialysis need to limit their phosphorus intake because, as we know, in the bones, calcium and phosphorus can combine and make a hard, solid mineral compound.

So in people with severe kidney disease whose kidneys aren't properly filtering out calcium and phosphorus, You can get these to combine together and precipitate, meaning forming a hard solid, and that can happen on the soft tissues of the body. So like our muscles, organs, and blood vessels, which we definitely do not want hard mineral solids on those parts of the body. So this is something that they really closely monitor for people on dialysis.

Uh, people on dialysis are asked to limit their phosphorus intake, but that is... pretty challenging since it's so widely found in foods that people with dialysis can actually take what's called phosphate binders. So it's a kind of chewable pill that they'll take with their food and that will help bind the phosphorus and it'll just be excreted in the feces. At least a portion of it will be excreted in the feces and will limit the amount that the body absorbs in an attempt to try to limit the amount of calcium phosphorus precipitate that can be happening inside the body.

Next, we'll talk about sodium. So we tend to think of sodium in a negative light because we know too much sodium is not good for us. However, sodium is an essential nutrient. We do need it to stay alive. So sodium is an electrolyte and it is really important.

in maintaining fluid and electrolyte balance. So we need the proper concentrations of sodium in the proper parts of our body. Sodium is the principal positive ion outside the body cells, as we can see in this picture. So we see a cell membrane and then we see what's outside of that cell.

And we see that we have a lot of sodium outside the cell, just a little bit of sodium inside. And then kind of on the opposite side, we have a lot of potassium inside the cell and not a lot outside. And so they kind of work together to maintain the appropriate amount of fluid in the appropriate places.

And so sodium helps maintain the proper amount of fluid outside of the cell. Sodium is also important in acid-base balance, maintaining pH, as well as muscle contraction and nerve transmission. So we know that sodium is related to increased blood pressure. So this slide explains why that happens. So as we've talked about before, electrolytes and fluid are really tightly linked.

And so essentially, that's why sodium is related to. blood pressure. So when you eat more sodium, you are going to have more sodium in the bloodstream. And so as we know, we need to keep the concentrations of certain electrolytes within a certain range. And we also know that water is going to flow to the place of higher concentration of electrolytes.

So water is going to follow sodium. And that means that we are going to have an increased amount of water in our blood vessels. And so we are going to have more blood in our blood vessels, but our blood vessels can only change size so much. They can't just kind of unlimitedly expand in order to, you know, take up that extra water.

So because our blood vessels aren't going to be able to expand enough to accommodate this extra water. it's going to increase the pressure in our blood vessels. We see that here on this image where we see our blood vessels staying the same size, but we have a higher volume of fluid that's flowing through these vessels.

And so that's going to increase the pressure. The recommendations for sodium are actually not a minimum recommendation generally that we think of, but are actually an upper limit. So for the average person, it's recommended to consume less than 2,300 milligrams of sodium per day. However, for people who have hypertension or pre-hypertension, kind of elevated... elevated blood pressure, but not to the point of actually having hypertension, these people are recommended to limit their sodium quite a bit more to 1500 milligrams of sodium per day.

So the upper limit for sodium is 2300 milligrams per day for adults, unless they have hypertension or pre-hypertension. Sodium is one of those things that is vastly over consumed in the US. So here we see the average consumption in males and females compared to the adequate intake, which the 1500 milligrams seems to be enough for most people. Most people shouldn't need to consume more than that. 2300 milligrams is the upper limit.

And then we have in orange, the average consumption of sodium in the US. So we see for males it's over 4,000 milligrams a day which is quite a bit more than the 2,300 milligram upper limit. For females it's about 3,000 milligrams a day, still quite a bit more than the 2,300 milligram upper limit.

So sodium in our food comes from a variety of sources. So first let's start on the left with unprocessed foods. So this is just the sodium that is naturally occurring in food, you know, as we might get it from nature.

So things like fruits, vegetables, meats, eggs, dairy, etc. Most foods are going to have a very small amount of sodium naturally occurring. So when you pull a potato out of the ground, when you get milk from a cow, there's going to be some sodium in it already. And so we can't remove any of this anymore. It's just there.

So these unprocessed foods overall contribute on average less than 10% of the sodium in the U.S. diet. And so we can see the amount of milligrams here. And once we compare it to the ones all the way to the right, we'll see that it's a huge, huge difference in the amount of sodium that's naturally occurring in foods. Versus what we might get in processed foods. But there is a small amount that is naturally occurring in foods.

About 15% of the salt that is consumed by the average American is added in cooking. So either while you're preparing your food or at that table where you are actually using the salt shaker. So we see here that one teaspoon of salt, you know, from the salt canister is going to provide us with 2,300 milligrams of sodium. So one teaspoon of salt, um, is the upper limit for the day.

Um, so that will just kind of help you keep in mind, uh, kind of what it might look like of pure salt to meet the, uh, the upper limit. When you're looking at a salt shaker, it has about 100 milligrams per shake. Obviously, that'll vary a bit by what type of salt shaker you have, but that's what we can think of about on average. And again, about 15% of the sodium consumed in the US is either added while you're cooking your meal or at the table.

But 75%, the vast majority... is actually found in processed or packaged foods. So it's already in there by the time you bring it home.

So this is where generally we tell people who would like to reduce their sodium intake to try to watch out for. So either reducing processed packaged foods overall or trying to find those that are lower in sodium. So there are going to be some that are just kind of always really high in sodium.

So things like pickles, um, here we have ham, uh, things like fast food, uh, frozen meals, box macaroni and cheese, et cetera. All of those tend to be really, really high in sodium, um, and are generally recommended to limit on a diet. reduce sodium diet. Here we also have some canned vegetables. That is one where you can actually find lower sodium versions.

So that would be one that I wouldn't say just to totally get rid of. That would be one to watch out for, which we'll talk about more in a minute. So kind of the general relationship between sodium content in food and the degree of processing. is that the more you process a food, the more you increase the sodium content.

So generally foods, you know, as you find them in nature are going to be relatively low in sodium. So here we have just, you know, plain rice doesn't have any sodium. An apple may not have any sodium. Vegetable oil may not have any sodium, but a couple of these other things do have some amount of sodium naturally occurring. Um, milk is actually one of the foods that, you know, unprocessed foods that tends to be a bit higher in sodium, but still relative to as we, you know, ramp up the processing up fairly low.

But we see once we get into this kind of middle category, um, so something like a boxed rice pilaf, like rice or roni, you're increasing that up to 580 milligrams. Um, if you buy French fries, those have generally had sodium added. Um, margarine is going to have more sodium than oil. Cheese is going to have more sodium than milk. A, you know, more processed meat product like chicken nuggets is going to have more sodium.

But if you go, you know, all the way to the right, you'll see kind of the, the foods that we buy that are, you know, kind of ready to eat. Um, those tend to be really high in sodium. Um, so something like a bottled salad dressing, um, a, you know, canned soup.

Deli meat. Those are all foods that are really really high in sodium. So here we see How much sodium is in a variety of foods again? one teaspoon of pure salt is going to pretty much provide the upper limit of sodium for a day Some of those things that are you know, especially high in sodium are going to be pickles canned soups processed meats or deli meats.

Cottage cheese is one of those foods that's otherwise really healthy, but it does have a lot of sodium in it. So that's kind of the downfall of cottage cheese. But whenever you are buying kind of like canned, boxed, frozen things, those tend to be pretty high in sodium. So if you were to get some... canned tomato juice or jarred marinara sauce.

Those do tend to have quite a bit of sodium added. However, there are more products on the market now that are either no salt added or reduced sodium. So always just watch out when you're at the store looking at labels and trying to find the lower sodium versions of the things you like.

The upper limit of 1500 milligrams, that lower recommendation is generally put in place for people who are at higher risk of hypertension or high blood pressure. So people over 50 tend to be at higher risk of high blood pressure. People of African American or African ethnicity tend to be at higher risk of high blood pressure than other races or ethnicities. People who already have high blood pressure, people with diabetes, and people with kidney disease are all recommended to go with that lower level of sodium. So how to reduce your sodium intake.

So this is something that virtually anyone you meet is going to exceed the recommended amount of sodium. So this advice applies to pretty much anyone. So one way is to go out to eat less. Foods that you get going out to eat are... almost always going to be really high in sodium.

If you were to, you know, go to a salad bar and you were able to, you know, pick out all your vegetables and if they happen to have a... low sodium dressing. Like that would be one way that you might be able to reduce your sodium intake while going out to eat. But almost anything you get going out to eat is unfortunately going to be really high in sodium.

Cooking more from minimally processed ingredients is going to allow you to control what you're putting into your meals and is going to allow you to start with things that are really low in sodium. However, a lot of us don't have the time to cook all of our foods from scratch. So it is still really important to try to find the lowest sodium choices out of packaged foods.

So when you are buying packaged foods, whether it's something that's still relatively minimally processed, like canned beans or canned vegetables, or if it's something like a soup that's ready to eat that is more processed, Um, look for those that have lower sodium. So you can look for things that are reduced sodium or no added. And so, um, some of the really healthy choices, um, that are, you know, canned or frozen, um, things like canned beans, you can find reduced sodium or no salt added. Uh, same thing with other, other canned vegetables like canned tomatoes and, uh, you know, canned green beans, et cetera. Um, One thing to point out though, is that there are some foods that say reduced sodium, but they're still really high in sodium.

One thing that fits this bill is soy sauce. That is one thing that is just extremely high in sodium. So even if you were to get a reduced sodium soy sauce, it is still going to be high in sodium. It's just going to be lower in sodium than the kind of regular. version of it.

So you'll still want to, if you are trying to watch your sodium intake, you'll still want to watch how much soy sauce you're using. One of the things you may find if you are trying to reduce the sodium in your diet is that food is going to start to taste pretty bland if you do that. One of the things to try to make your food not taste so bland while you're reducing your sodium is to reduce the sodium in your diet gradually.

Don't just, you know, all of a sudden try to go to a no salt added diet. If you reduce gradually, your taste buds will start to adapt to less sodium. And you'll, you know, over time, you'll get to a point where if you were to eat something that may taste fine to you right now, after you've gotten accustomed to less sodium, that will actually taste way too salty. So you do start to get used to it and you can certainly do other things to try to make your food less bland too. At the same time, citrus or other acidic things like vinegar can be a good way to make your food have more flavor while you are reducing your sodium intake.

But also things like herbs and spices will certainly help there too. So some of the packaged foods to watch out for that are highest in sodium are listed here. This is certainly not all of them, but some of those that are higher, that are especially high.

So a lot of our frozen meals are going to be really high in sodium. But just if this is something that you really rely on because you're too busy or you just, you know, aren't, you know. super skilled at cooking.

Frozen meals can be a healthy choice. Obviously, they are not all made the same. Some are, you know, have whole grains and vegetables while others don't.

Look for frozen meals with lower sodium if you are, if that is something that's really important to you. But kind of the average frozen meals tend to be really, really high in sodium. Frozen vegetables, um if you are getting just a plain frozen vegetable that doesn't have any salt or seasonings or any sauce or seasoning those are typically going to be no salt added but if there is a frozen vegetable that might have a cheese sauce or something like that um those may have a lot of sodium added um but always just look at your labels to see um different brands different flavors are going to have different amounts of salt added to them canned soups and broths like vegetable broth chicken broth beef broth um all tend to be really high in sodium um but certainly there are more products on the market now that are going to be lower in sodium um some even have uh no salt added uh deli meat and processed meats uh things like bacon ham sausage these are some that are pretty much always going to be really high in sodium. They don't, at least to my knowledge, have lower sodium options available at this point. Canned vegetables and beans, these kind of standard versions that you get are going to tend to be pretty high in sodium, but obviously vegetables and beans are healthy foods.

Canned choices can be cheaper, more convenient. uh, they, they don't go bad. And so you don't need to worry about, um, you know, just keeping some on hand.

You can always have those ready for you. Um, if you don't have any fresh or frozen vegetables around. So these can be really good choices.

Um, but the sodium content can be pretty high. Uh, again, you can always look for, uh, no salt added or lower sodium versions, but if you can't find those easily, um, if you drain and rinse, uh the regular versions of these um that will remove um a good portion of the sodium so some of the sodium is going to be kind of absorbed into the vegetable or the bean and that you can't remove but some of them um uh some you will get rid of a good deal of the sodium if you drain in from them condiments and sauces are another category of foods that tends to be really really high in sodium um Things like ketchup, stir-fry sauces, soy sauces, you may be able to find lower sodium versions, but something like soy sauce, even a lower sodium version is still going to be really high in salt. Salad dressings that are, you know, bottled do vary quite a bit. Some are going to be super, super high in sodium. Others are actually really low in sodium.

So again, it's all going to be down to kind of looking at those labels to see. If you can find a low sodium version, uh, snacks like chips, uh, pretzels, uh, goldfish crackers, things like that, uh, tend to be really high in sodium. Um, breads are another one that we don't think of as tasting salty, but they do have a fair amount of, of salt in them. Um, so this is things like, uh, sliced bread, loaves of bread, um, buns, et cetera. Those all tend to have a decent amount of sodium in them.

And especially if you're someone who might eat toast for breakfast, a sandwich for lunch, and maybe some bread with dinner too. That will definitely add up over the day. And then lastly, we have our brined foods.

All of these are going to be really, really high in salt. And there generally aren't a lot of low sodium options here for things like pickles, olives, and corned beef. So while it's really, really rare to not get enough sodium, there is a possibility to get sodium deficiency, which we talked about in the water section. So this is called hyponatremia.

And this is where typically we don't think of it as just a dietary deficiency. This is going to be something that happens with athletes who are doing um, really intense endurance activity. So something like a marathon or an ultra marathon.

And so hyponatremia means low sodium in the blood. So what's happening with someone who's doing a really intensive, long endurance activity is they are sweating a lot. So they are getting rid of a lot of electrolytes like sodium.

And they're also drinking a lot of fluids and so that is going to be diluting the sodium in their body so especially if they are just drinking water and they're not drinking a sports drink or something else that is going to provide them with electrolytes um they could end up having low sodium in their blood um as we talked about that this can um be fatal this um this can be really serious you And so this is one reason why it's really important for people doing those really intensive endurance activities like marathons to have something with electrolytes, whether it's a sports drink or a tablet that has electrolytes when they're doing their activity instead of just water. So next we will talk about potassium. So this is... Pretty closely related to sodium in the body.

So potassium is the principal positive ion inside the cells, and it maintains the appropriate amount of fluid inside the cell. So sodium and potassium work kind of together on things like fluid balance, nerve impulses, and contracting muscles, including your heart. And so if you have taken biology classes before, you may have heard of the sodium potassium pump.

And so that is a transport protein that goes through the membranes of cells that is going to be responsible for transporting both sodium and potassium. And so they're tightly related in the body. Potassium can also be used to reduce some of the effects of sodium in the body.

So if someone is eating a lot of potassium, that may reduce the amount that sodium is able to reduce the... I'm sorry. If you have a lot of potassium intake, sodium is not going to impact your blood pressure as much. So high potassium intake promotes getting rid of extra sodium. Um, so you're not going to keep as much sodium in the body.

Uh, you're going to excrete it through your urine and it is going to reduce the, uh, amount that excess sodium is able to impact your blood pressure. And so we know that potassium intake is associated with lower blood pressure. Uh, potassium is found in highest amounts in, um, our whole plant-based foods.

So things like fruits and vegetables, uh, beans, but also is found in, uh, pretty high quantities in dairy. Um, so if you eat a, um, a variety of fruits and vegetables, you will be getting, um, a good source of potassium. We always think of bananas as being one of the highest potassium foods, but if we look at this graph, we see that there are also several other fruits and vegetables that are really good sources.

So potatoes are actually an excellent source of potassium. One medium potato with skin will provide us with about 30% of our daily potassium. Beans... are a great source of potassium but also things like orange juice tomato sauce and broccoli too the recommendation for potassium is 4 700 milligrams per day quite a bit and most people do not come anywhere near that we know that people eat far less than the recommended amount of fruits vegetables um and legumes.

And so that contributes to the low potassium intake in the U.S. Potassium deficiency is really rare. It's generally not something that happens from diet. Our body's really good at regulating potassium in the body. So it is not generally going to be from a dietary deficiency that you would end up with low potassium in your blood, which is called hypokalemia.

but it can happen with, um, some other medical conditions. It is a life-threatening condition. Um, it can cause weakness, fatigue, irregular heartbeat, and, um, eventually death. Um, but again, it's generally not going to be from, um, anything related to the diet. Uh, so people who might be at risk of a potassium deficiency in the blood, um, include people who are on it.

certain drugs to treat hypertension. So sometimes diuretics, which are medications that are going to cause you to excrete more fluid, basically you are going to urinate more, getting rid of more fluid. That'll also get rid of some of the electrolytes in your body too. And these are sometimes used to treat hypertension or high blood pressure. Certain diuretics are going to deplete potassium in your bloodstream.

And so doctors will usually monitor this and also sometimes give people a potassium supplement in addition to their diuretic in order to prevent this from happening. But people with eating disorders who are doing things like vomiting or laxatives, These can really throw off your fluid and electrolyte balance, which can put people at risk for life-threatening issues related to fluid and electrolyte imbalances, including potassium. Potassium toxicity can also occur, and when you have high potassium in the blood, this is called hyperkalemia, which is also life-threatening. Again, this generally is not going to happen due to diet. Healthy people are able to regulate excess potassium and are able to just get rid of it.

However, people with heart conditions, people who take incredibly high dose supplements or infants who may not be as good at regulating potassium in the body, this can be a life-threatening condition. So we will talk about the DASH diet later in the semester, but I wanted to just really quickly bring it up while we are talking about sodium and potassium. So the dietary approaches to stop hypertension diet is a diet that is specifically formulated to reduce high blood pressure.

And so one of the kind of cornerstones of this diet is that it's high in potassium, but low in sodium. And so it's, um, an effort to try to, um, use those electrolytes to your favor to, um, reduce blood pressure. And so it's really, really heavily focused on, um, foods that are high in potassium, like fruits and vegetables, low fat dairy, um, and low in sodium. So magnesium is also another mineral that is really important in our bones. So 60% of the magnesium in our body is stored in our bones.

The rest is in our muscles and some other tissues. Magnesium is one of those minerals that is really important to serve as a cofactor for enzymes. As we talked about, cofactors are those things that are beyond the protein. that are needed for that protein to have its enzymatic function.

It kind of will fit into that protein. It will get added later after that, you know, all the amino acids have been added after, you know, the protein has been freed from the ribosome. A magnesium molecule will get added to some proteins and that will cause that enzyme to be able to... do the chemical reactions it needs to do. So magnesium is used for a ton of different enzymes in the body.

Some of those enzymes are part of energy metabolism. And magnesium is also important for muscle and nerve function. Deficiency of magnesium is very, very rare, especially from the diet. It's something that we don't really see, but deficiency can cause muscle cramps. and seizures.

Magnesium deficiency in the body can happen with certain medications and also with alcohol use disorder. Magnesium is found in a variety of foods, but especially things like nuts, green leafy vegetables, beans, milk, and whole grains. Toxicity is not really something we worry about.

Like with most, most of them would nutrients we talked about, except from high intake from supplements. Now we'll move on to the trace minerals. So these are the minerals that are needed in quantities less than 100 milligrams per day, whereas everything we've already talked about are things that we need in greater quantities than that. So we have the list of the trace minerals here. We're only going to talk about three in detail.

iron, zinc, and iodine. So iron, as we've talked about a bit already, iron is really important for oxygen transport in the body. Iron is part of hemoglobin in red blood cells.

So here we see on the left a picture of the hemoglobin protein. And we use this as an example in the protein chapter of a protein that has several different subunits, which we see here in the two red subunits and the two purple subunits all coming together to form the full hemoglobin molecule. So in each of the subunits, you have what is called heme. And that is this kind of bigger picture we see here. So heme is a molecule.

That is going to have an iron at the center, which is what we see here with this FE. So that is how we show iron on the periodic table is with FE. So each one of these separate subunits is going to have an iron in it.

And that iron is going to be able to bond with oxygen and transport oxygen throughout our body on the red blood cells. We also have a similar protein in our muscles called myoglobin, which we see on the top right. It's just a single subunit.

It's pretty similar to the single subunits of hemoglobin. It also is going to be able to transport oxygen, but it is only found in our muscle cells. In addition to oxygen transport, iron is involved in several other processes in the body.

including as part of enzymes used in energy metabolism. It's also important for the synthesis of neurotransmitters, which is important for brain development. And it's also needed for production of immune cells. So iron in food is found in two different forms. So as we just talked about, the form of iron that is found in hemoglobin and myoglobin is called heme iron.

And here we see kind of a more chemical structure of what the heme molecule looks like. And then at the center of it, we have iron. And so this is what we call heme iron, is iron that is found as part of the part of this heme molecule.

So heme iron is found in hemoglobin and myoglobin and thus is only going to be found in animal flesh foods. So things like beef, chicken, fish, pork, those types of foods are going to have heme iron. You're not going to find heme iron in things like eggs or in any plant based foods. Heme iron is the most bioavailable form, meaning that we are able to absorb it the best when compared with non-heme iron.

So non-heme iron is not part of this heme molecule. So it's the type of iron that is all of the iron found in plants. So things like beans and grains, all of the iron in those types of foods are going to be heme iron.

And And then all of the iron in eggs is also non-heme iron. So animal flesh foods, though, however, have a mixture of both heme iron and non-heme iron, as we see in this top right picture. So in our animal flesh foods, which is meat, fish, and poultry, 60% of the iron is non-heme iron. Whereas for... 40% of the iron in it is heme iron.

So in contrast, our plant-based foods, again, things like beans and grains, as well as eggs, all of that iron is non-heme iron. And that non-heme iron is not as bioavailable, meaning that we do not absorb it as well. So iron in foods is found in high amounts in beef. So red meat is actually the animal-based, animal-fleshed food other than a few particular types of seafood. There's more iron in beef than there is in chicken and poultry.

However, there are kind of a couple seafood sources of iron that are really high. So things like clams. Those have a ton of iron in them.

When we are talking about our plant-based sources, those that tend to be the highest are beans, certain leafy green vegetables. Some grains have a decent amount of iron, but then you'll also find a lot of foods that are fortified with iron, meaning that they have iron added. So something like life cereal or Wheaties may have quite a bit of iron added to it.

So while the last slide, we looked at just like the pure quantity of iron in food, remember that it is going to not all be absorbed the same. So not all iron from food, you're not just going to want to pay attention to the amount of iron that the food label says is in there. You also need to pay attention to how well that it... it is absorbed by the body.

And again, this is what we call iron bioavailability. Um, iron is one of the, the more complex things in the body with regards to bioavailability. So there are a lot of things that, um, may increase absorption, a lot of things that may decrease absorption.

Um, so, uh, iron status in the body, um, is basically how much iron you have in your body. Do you have enough? Are you what we call sufficient or do you not have enough?

That's what we would call deficient. So if you are deficient, you are actually going to increase absorption. It's your body trying to make sure that you are getting enough.

So you are going to absorb more iron from a food. It's going to be more bioavailable if you are deficient. Um, also if you are someone who... has a high need for iron, you will tend to absorb more as well.

So anyone who is undergoing blood loss, so this could be just people going through menstruation. It could also be someone who, you know, potentially they got a cut, you know, a wound where they lost a lot of blood or someone who is having a, you know, chronic. bleed from their gastrointestinal tract, which we actually do see quite frequently. So anyone who's losing blood for whatever reason has a higher need for red blood cells.

And so they're going to be able to absorb iron better from their food. But some other things are also going to increase the need for iron. So people who are living at high altitude, actually, because there's less oxygen in the air, they're going to need more red blood cells to be able to transport oxygen throughout their body.

So people living at high altitudes are able to absorb iron a bit better. People doing really intense physical exercise like elite athletes may have higher iron needs. Pregnancy certainly increases iron needs.

And if you have iron deficiency anemia, if you are actually deficient in iron, you are going to absorb iron better. Um, similarly, if you have low body stores of iron, so iron is something that we store in our liver. If we don't have very much there, our body is also going to try to, uh, make sure that we have enough and increase our absorption of iron. Um, on the other hand, um, if you have plenty of iron in your body, if you have a high, high amount of iron stores in your liver, you you don't need as much and so you are going to not absorb as much so your body does a decent job by trying to kind of protect you as much as possible from either too little iron or too much iron um so heme iron in food again is going to be that iron that is solely found in animal flesh foods but only makes up a portion of that iron um that is absorbed much, much easier than our non-heme iron.

And also that heme iron is not going to be impacted by these other things in these black boxes. So heme iron absorption or bioavailability is not impacted by things like vitamin C, polyphenols, et cetera. So all of these things in these black boxes are factors that only impact non-heme iron absorption.

So it's that non-heme iron that the amount that we absorb is highly impacted by all of these other things. So if you are eating vitamin C at the same time as you're eating something with non-heme iron, you will actually absorb more of it. If you're also eating a source of non-heme iron like... beans or whole grains, if you are eating that at the same time as something as either meat, fish, or poultry, which we call the meat, fish, poultry factor, if you eat plant-based sources of iron at the same time as you're eating meat, fish, and poultry, you're actually going to absorb more of that non-heme iron, which is really interesting. However, kind of on the decreasing absorption side, we have a ton of different things that will actually reduce our ability to absorb iron, which some people don't need to worry about.

Other people though, who may have iron deficiency or be at risk of iron deficiency will want to pay attention to these things. So phytic acid is a compound found in certain plant-based foods. So whole grains and legumes. It's not something that's actually unhealthy for us. But for people who need to really pay attention to making sure they're getting enough iron absorbed into their body, it's something that they need to think about.

So whole grains and legumes have something that will actually decrease absorption of iron. Oxalic acid or oxalates is another compound found in some plants, particularly some green leafy vegetables, spinach and Swiss chard in particular. are especially high in oxalates.

So while you may see that spinach is considered a decent source of iron, not much of that is actually absorbed. So if you are someone who may be a vegetarian or a vegan, there are definitely better foods that should be considered as sources of iron other than spinach and Swiss chard. Polyphenols, again, are one of these phytochemicals. Classes of phytochemicals. So they are health promoting foods.

They are health promoting compounds. They are good for us. However, they do decrease iron absorption. And so polyphenols are found in tea, coffee, red wine, and a bunch of other foods.

If you have reduced gastric acidity, so people with various health conditions may not produce as much stomach acid. And so if you produce less stomach acid, you don't absorb iron as well. And then lastly, if you have excessive intake of other minerals like zinc, manganese, or calcium, that can reduce the amount of iron you're absorbing.

As we talked about a few times this semester, some things compete for absorption in our small intestine. So certain minerals are going to absorb through the same places. And so if you have a ton of one, it's going to reduce the amount of iron you're absorbing.

reduce the amount that you absorb of another. So if you are someone who is at risk of iron deficiency or you do know that you are iron deficient, this could be someone who's a, you know, for example, vegan, vegetarian, or, you know, for whatever other reason that you are iron deficient, here are some ways that you can try to increase your absorption of iron. Eating vitamin C rich foods with sources of iron. So if you, um, are eating something like, uh, you know, strawberries, bell peppers, orange juice. Um, if you have that at the same time that you're eating a source of iron, like, uh, uh, beans, um, whole grains that can help you absorb more of the iron from those foods.

Uh, don't drink coffee or tea with meals because those have those polyphenols that reduce iron bioavailability. Uh, don't take other mineral supplements at the same time as iron supplements. So for example, if you need an iron supplement, don't also take a calcium supplement at the same time that will decrease the amount of iron you will absorb from the calcium.

Also just a note, you don't need a supplement unless you are deficient. Um, there are plenty of people who may be on a vegan or vegetarian diet who, um, for whatever reason, uh, they... are not iron deficient, they're doing just fine.

So if you're in that boat, then even if you're a vegan or vegetarian, you don't need a supplement. However, if you are a vegan or vegetarian and you are iron deficient and take a supplement, then don't take it at the same time as other mineral supplements you might take. So wanting to absorb more iron, this isn't something that everyone needs to do. Only people who...

may be at risk of iron deficiency need to really focus on this. Um, so, um, biological females of childbearing age. And so essentially we are talking about people who are having a menstrual period.

Um, those are the people who have the highest iron needs, um, because you are needing, you're, you're losing iron every month. Um, so when we look at the RDA for iron, we'll, we'll see that it's much, much higher. for biological females of those menstruating years. Additionally, during pregnancy, iron needs are really elevated as well. And so iron deficiency during pregnancy is fairly common too.

So iron deficiency is the most widespread mineral deficiency worldwide. And it's one of the few deficiencies that we actually do see. pretty commonly in the U.S.

And so the deficiency disease we see with iron deficiency is called iron deficiency anemia. It's where you have low hemoglobin in your blood. So with iron deficiency anemia, you'll see fatigue. So basically you'll be tired. It's difficulty to get through your daily activities because you just get really tired.

It can also negatively impact the immune system as well. Iron deficiency is particularly of concern for children because it's important for cognitive or brain development. And so, iron deficiency during young children can end up with cognitive or developmental impairment. So people who are at risk of iron deficiency, it's a pretty wide amount of people. So those who have low dietary diversity, which we've talked about with especially low income, more developing countries where people rely really heavily on a few staple crops.

So these people are going to tend to be eating a lot of just baby rice. um, cassava, uh, corn, something like that, that is, um, not a great source of iron. Um, they're not eating many, uh, animal flesh foods. And so they're not getting a great source of iron in the diet. Um, so that's why iron deficiency is one of the, uh, most serious deficiencies worldwide.

Um, but outside of that, um, these other, uh, categories of people, um, we will find in the U.S., so you may see iron deficiency among these groups of people. Premature infants are born before iron has been transferred to the fetus, and so most of the iron transfer actually happens late in pregnancy. So if they're born before that happens, they are going to be born pretty deficient in iron. Iron deficiency can be more common among young children during pregnancy. vegetarians, vegans, as we talked about.

Again, biological females of childbearing age, people during the menstruating years. Iron deficiency becomes pretty rare after menopause though. So after people have stopped having menstrual periods, iron needs go down and iron deficiency becomes pretty uncommon. People who have especially heavy menstrual periods are at increased risk of iron deficiency, again, because they have a higher need for red blood cells because they are losing red blood cells very frequently.

Any other kind of condition where you are going to be losing blood is also going to put you at risk of iron deficiency. So people who donate blood frequently may be at risk of iron deficiency. And also, One of the more common causes of blood loss we have is from a GI bleed. So it could be in the stomach, it could be in the intestines, but there are various conditions that will cause people to have bleeds. Often not really severe acute losses of blood at one time.

It might be kind of a slow bleed over a longer period of time. That can cause people to become iron deficient as well. And so iron deficiency is measured by your hemoglobin in your blood. This is one of the really, really common blood tests.

So if you get, you know, annual blood tests, this is probably something that you're going to get measured. And so your doctor should tell you if one of these kind of routine tests show that you are iron deficient. Iron toxicity is also a concern.

It is one of the most toxic micronutrients. So it is one of the most common to also have accidental overdoses. So iron pills are often red, like you see here, and they can, especially to children, look like candy.

And so there are certainly instances where children may, you know, stumble upon a bottle of iron pills and take a whole bunch thinking they're candy. And so it is the most common poisoning in children and it can be fatal. So it's really important to make sure that you keep supplements containing iron out of reach of children. There is also a condition called hereditary hemochromatosis.

And so this is a genetic condition where people are going to absorb kind of an abnormally high amount of iron. Their body is not going to normally, if you don't have this condition, your body prevents you from absorbing too much iron because excess iron is very toxic in the body. However, people with this condition, their body... doesn't kind of turn that off.

You just always absorb a really high amount of iron. So people with this condition may need to reduce the amount of iron they get from their diet. But then also the way this is treated is just blood donation. So essentially just taking out those red blood cells periodically, forcing your body to use up more iron to replace them is actually a very effective treatment for this condition. So signs and symptoms of toxicity of iron include bloody vomit and or diarrhea, organ damage, and this is certainly a fetal mineral toxicity if it is severe and untreated.

Zinc is another one of those minerals that is used as a cofactor for enzymes. It's used in 300 enzymes in the body and participates in thousands of chemical reactions. It is especially important to create DNA and RNA. It is an antioxidant in the body, meaning that it will kind of... prevent those free radicals that we talked about in the vitamins chapter.

It can help prevent those free radicals from damaging the body. And it's also essential for producing that hemoglobin molecule that is going to get put into the hemoglobin protein. So zinc is found in really high amounts.

in seafood, but also in red meat. So people who are eating, um, animals are generally going to have ample amounts of zinc. Um, it's also found in things like nuts, legumes, and whole grains.

Um, so vegetarians and vegans also are able to get sources of zinc as well. Um, plant-based sources are not as well absorbed though, kind of similar to what we saw with iron. Um, But it's not as much of a nutrient of concern for vegetarians and vegans, in the US at least, as we are concerned about with iron. So zinc deficiency outside of the US though is one of the more prevalent nutrient deficiencies worldwide. So again, especially in developing countries who are not eating much animal flesh foods, so people- may not be eating much meat, fish, or poultry, and may also not be having much milk.

Zinc deficiency can cause what is called stunting. So as we see in this picture here, this youth is only about four feet tall at 17 years old. And so zinc deficiency can cause what's called stunting or stunted growth.

zinc deficiency also negatively impacts the immune function and it can cause diarrhea, which is, um, as we talked about, um, earlier in the semester, there's that, uh, kind of cycle of malnutrition and, um, infectious disease that they just make each other worse. And so zinc deficiency, um, can, uh, end up, um, with putting people, especially young children at risk of severe diseases that would normally not. be very, uh, very harmful to the body. But, um, when you have this cycle of malnutrition and infectious disease, diarrhea, um, they can end up being fatal. Uh, so zinc toxicity can occur with really high supplemental intake and can cause vomiting, diarrhea, and headache.

Now we will move on to iodine. So iodine is a mineral that is needed for your thyroid hormone. Your thyroid is a gland that is located in the throat region.

And it produces several hormones for the body. And as we've talked about throughout the semester, hormones are really important for regulating body functions. So thyroid hormone regulates what's called your basal metabolic rate. So essentially kind of how many calories you're burning at rest.

So when you're not doing much, most of your calories are still from, you know, just those basic things that your body needs to do to keep you alive. So it regulates your basal metabolic rate. It regulates the body's temperature and is also really important for growth among children. So iodine is not found in a lot of foods.

Naturally, it is found in highest amounts in things like dairy and things that come from the sea because iodine is really high in salt water. So seafood will provide iodine. Seaweed has really high amounts of iodine.

But a lot of the iodine in the U.S. is going to come from iodized salt. So it's mandated that kind of normal salt, not sea salt, but kind of your typical salt, is going to contain iodine in the U.S. And so it's fortified.

It has been added to it. And so a teaspoon of iodized salt is going to provide several times the RDA for iodine in the U.S. And is one of the more common. sources of iodine in the US.

Iodine deficiency is not common in the U.S., but it is one of those common deficiencies worldwide. So here we see a graph of where there is the most severe iodine deficiencies worldwide. So iodine deficiency can cause what's called...

goiter, which we see in this woman, um, with the lump in the, uh, the, the neck. Um, and so you have your thyroid gland, um, becoming bigger and bigger and bigger until it becomes quite visible, um, that it has gotten larger. And so what's happening here is when you don't have enough iodine, there's a, uh, hormone that's released called TSH, uh, thyroid simulating hormone.

That is going to stimulate your thyroid to get larger in an attempt to try to trap more iodine. And if you don't have much iodine in your body, it's just going to keep getting bigger and bigger and bigger in an attempt to get more iodine. But if there's just not any iodine there, it's not going to be able to do that.

So there are... several symptoms of iodine deficiency, uh, slowed metabolism, um, meaning you're burning fewer calories. So you will, um, often see weight gain, um, happening with iodine deficiency, um, because of iodine's role in temperature regulation, uh, people with iodine deficiency will also feel cold and then it can also cause depression. Iodine deficiency, um, during iodine.

Pregnancy can also have some serious impacts on the baby being born. So congenital iodine deficiency syndrome causes impaired fetal brain development and growth. So you will have intellectual disability, loss of hearing and speech, and also very short stature.

Iodine toxicity is very rare, but It can occur from really excessive intake from supplements. Similar to iodine deficiency, you can see an enlarged thyroid and it can also be fatal.

Transcript for:Understanding Major and Trace Minerals

Transcript for:
Understanding Major and Trace Minerals