in our next unit we will be discussing the vitamins and the minerals so in this presentation we're going to start off with the fat soluble vitamins initially though I want to present some facts about the vitamins as a group so some facts to start off with they are our fourth essential nutrient they are the first of our micronutrients so we've talked about the three macronutrients so far vitamins will be the first of the micronutrients despite being micronutrients they are still essential for us and they're very important for us a lot of our chronic disease states are associated with low intake of vitamins I wanted to give you a bit of background on these as well pretty interesting stuff we've really just learned about vitamins over the last 100 to 150 years there's 13 of them there's four of the fat soluble and then nine water soluble and they were named in the order they were discovered so vitamin A was the first one all the way on down to to vitamin K the term V means vital it means essential so if you recall from our first presentation the term essential means we must get it through the diet because number one our bodies don't make it or enough of it and number two there's physical symptoms that occur without that compound so vitamins fall into this category and and then a final introductory note here a deficiency of vitamins can be mild this is sometimes referred to as marginal or it can be very severe so in our nation we tend to see more of the milder marginal deficiencies although there are some disease States as we'll learn that are associated with some pretty severe deficiencies okay so let's talk about vitamins are they organic what do you guys think yes they are organ organic they contain a carbon molecule next question for you do they have calories no right they do not have any calories they help metabolic reactions along that get us calories that get us ATP but by themselves they don't have calories uh each one is actually pretty unique in their chemical structure we'll see that as we progress through the the next couple of presentations another characteristic that is worth mentioning they don't need digestion so remember learning about the macronutrients and how we break those down in the system before we absorb them the vitamins themselves are absorbed intact we do have to break them off from the food that they're contained in however as a whole they're absorbed right across that micro border and then another characteristic worth mentioning uh vitamins can be destroyed readily uh we didn't see this with our macronutrients H those are pretty stable compounds but vitamins can be destroyed by things like heat uh light we'll learn about some vitamins that are sensitive to UV light oxidation and water soluble more so than the fat soluble tend to be more sensitive so some tips I wanted to share with you and these are a couple of these are outlined in your textbook as well uh we recommend as dietitians to cook in the least amount of water possible that's going to prevent some of these vitamins from being leaked out into the water and then discarded another tip for preserving vitamins is to uh use methods like steaming or microwaving over frying because it's not going to be quite as a high heat the the higher heat that these are exposed to the more likely they are to be destroyed another interesting tidbit might be for you to add your vegetables to Boiling Water rather than putting them in the water and then waiting for it to boil a couple of others for me as a dietitian uh with your oils it's recommended to store those in a dark cabinet to prevent the light from hitting the the vitamin E in particular and then one that I'm asked about a lot is produce so how do we store produce you can certainly store it on the counters however to preserve the vitamins as much as possible it is recommended to store them in a cooler environment so potentially the refrigerator okay so those are some tips and strategies for you in terms of preserving the vitamins so again a recap they're organic no calories they don't need digestion and they're more prone to being destroyed than the other nutrients provitamins versus pre-formed vitamins concept that we'll talk about with our first vitamin today provitamins are precursors they're not yet active when we consume them but inside the body that compound that provitamin will be converted to the active vitamin whereas pre-formed vitamins these are already in their active form when we consume them lots of functions goodness there's so many functions of vitamins and minerals as well we could throw them into the discussion here something I wanted to note with these functions and these roles they often work together they support one another in their roles this is one of the reasons why individual vitamin supplements are often not recommended or even indicated many times we get the best benefits when we're eating Whole Foods where those compounds can work together I included the B vitamin main function here on the right hand side just as a reminder we've covered metabolism in this course so keep in mind the B vitamins all of them have a key co- enatic function and what that means is they are responsible for helping those metabolic reactions occur if we didn't have riboflavin or nasin in some of our carbohydrate metabolic reactions we wouldn't be able to have that catabolism or even anabolism occur so key point to keep in mind with those B vitamins very very important for enzyme action okay I wanted to include a bit here on antioxidants many of our vitamins are antioxidants so what are antioxidants well these are a natural defense mechanism natural compound in the body that contains oxygen and antioxidants can help neutralize what's called free radicals and free radicals we're going to show or I'm going to show you a short two-minute clip here about free radicals and how they can be uh detrimental for our health so let me go ahead and pull up your eext and play this quick video on free radicals free radicals are unstable molecules that can cause a make it a little bit bigger here for us chain reaction of in stability in surrounding compounds the damage caused by free radicals is considered a factor in increasing the risk of heart disease and cancer and the Damage accumulates with aging free radicals are formed when the bonds of a molecues split in a way that leaves an odd unpaired electron they can be formed during various metabolic processes exposure to air pollution exposure to UV rays cigarette smoking Etc for example an oxygen molecule normally contains eight electrons sometimes during oxidation reactions oxygen will accept an unpaired electron the molecule becomes unstable and highly reactive because there is one or more unpaired electrons in the outermost shell free radicals inadvertently damage surrounding stable compounds by stealing an electron to recover their stability the compound from which the electron is stolen then itself becomes unstable and a chain reaction occurs when free radicals are formed in cell membranes they steal electrons from the phospholipid layer this results in damage to the lipid molecule and generates more free radicals once the lipid molecule is destroyed the cell Integrity is lost and the membrane can no longer repel water antioxidants vitamins like vitamin C vitamin E and beta carotene are compounds that can donate electrons to stabilize free radicals without themselves becoming unstable when present antioxidants stop the chain reaction and potential cellular damage by providing the free radical with the additional stabilizing electron fresh fruit and vegetables are natural sources of antioxidants a balanced diet that includes 5 to eight servings of fresh fruit and vegetables all right I'm going to stop her there so pretty cool those antioxidants can be literally a lifesaver for many individuals so let me get back on my PowerPoint here so a couple of highlights from the video free radicals unstable molecules they damage the cell's DNA they damage the structure of that cell the problem that we find is if we have too many of these free radicals in our system our bodies can't neutralize them well so we might be getting in some antioxidants but we're not combating those free radicals uh well this can lead to a state of oxidative stress which we're seeing that oxidative stress inflammation connection with so many of our chronic conditions so just as a side note where can we get free radicals I'm sure you guys have heard of things like UV light so tanning beds those are sources of free radicals but we also can get these through food so eating too many chemicals or processed foods can increase our free radical consumption um excessive alcohol intake Smog or pollution and then the biggest source interestingly enough is metabolism so when we're undergoing our regular metabolic reactions we are producing some of these free radicals so it's a normal natural process for the body but that's why it becomes so important to have adequate antioxidants in the system in our nation we have high exposure to free radicals high amounts of oxidative stress but unfortunately a low antioxidant Rich diet uh going along to my next Point here plant-based foods are generally where we find a lot of these antioxidants so on the clip they mentioned vitamins a c e there's also some minerals that are found in plant-based Foods the table I included here is of phytochemicals these are compounds that are found in plants that can help work as antioxidants and you can see here the different colors we always recommend eating across the rainbow to get in various pigments that have these phytochemicals in them and then Foods I mentioned plant-based foods but also keep in mind Foods first we don't find the same benefits of consuming these whether they're vitamins minerals or whether they're compounds like this in a supplement form we just don't get that same benefit all right so that's a little bit on antioxidants let's now go into differentiating the fat and water soluble vitamins and then in my next section we'll actually Dive Right into the first fat soluble vitamin so one thing that I wanted to make note of here in bold is bioavailability this is a concept that basically it's defined as how well a vitamin is absorbed in the body and used in the body uh bioavailability can differ from vitamin to vitamin and there's many factors that can influence bioavailability uh for example animal or plant Foods so with animal Foods we tend to find that the vitamins are more bioavailable whereas in plant-based Foods those vitamins may not be as available to the body due to fiber we learned about how fiber tends to bind other compounds fiber can also bind some of our vitamins when they're in the same food together so that's an example of a bioavailability difference uh what I wanted to mention here is in general the fat soluble vitamins ad and K are less bioavailable to us than the water soluble and we'll see that with the digestion and absorption figure on the next slide there's a lot of steps that we have to go through to absorb fat soluble vitamins and the more steps we have the more there is an opportunity for them not to occur as well so let's go ahead and look at digestion and absorption and then we'll we'll go back to my previous slide so this figure is taken from your textbook and it walks us through what occurs when we're absorbing those nutrients across so with our fat soluble vitamins we've got got to break them off from the food that they're in and then they go into the uh similar to the fats digestion absorption mechanisms so we need bile there we need them to be formed into my cells they are then absorbed across the inos site lining put it into kyom microns and then the lymph system that's a lot of steps right there and this is why we find that only about 40 to 90% of our fat soluble vitamins are absorbed uh folks who might struggle with absorbing fat soluble vitamins are folks who have some GI conditions we talked about several conditions like Crohn's disease IBS celiac disease so if there's any kind of malabsorption condition or inflammation in the GI system this may not work as well likewise if someone has a problem with their gallbladder and it's not producing or it's not releasing bile as readily that can also affect how well these are absorbed and then a final example someone who's not eating a lot of fat in their diet so if we have someone who's really restricting fat then we don't see the absorption of those vitamins occur as readily so again 40 to 90% are absorbed with our water soluble vitamins you can see pretty easy right on through into the bloodstream we find that about 90 to 100% of those vitamins are absorbed and where are they absorbed in the small intestine primarily the dadum and the janum so the first couple of SE ments of the small intestine so a lot of these other points I've already covered so just in brief here transport this means which system is transporting them I trust you guys can differentiate lymph versus cardiovascular uh storage we don't have a storage site for many of our water soluble vitamins there's only one B12 which we do have a storage site for but other than that they're pretty much excreted out through urine whereas our fat soluble vitamins we tend to store some extra amounts of those in our liver and even in our fat cells in our triglyceride stores I'm going to go on down to my last Point here with daily needs we often find that we don't need to take in the fat soluble vitamins on a daily basis because we can store some of them in our liver or in our fat cells whereas our water soluble ones these are the ones that are recommended to consume daily because we're not able to store them in the system and then my final Point here the toxicity Point really anything over 10 times the RDA for many of these is considered toxic and it's not necessary more is not better when it comes to vitamins uh the fat soluble ones tend to be more toxic so when we are differentiating them these are more toxic because they are stored in the body so if I massively overdo it on vitamin C I might have some diarrhea but that that's going to be about it whereas if I overdo it on vitamin A I can even create some damage over time okay so I hope this has been interesting to overview vitamins as well as start getting into the differences with fat and water soluble in the next presentation I will cover vitamin A