in this video I'm gonna be talking about the fat soluble vitamins this is the long awaited sequel to the water soluble vitamins video that I released a few months ago now fat soluble vitamins are really not too confusing and there's only four of them that you need to know for USMLE and comlex so as I present this to you I'm really just gonna walk you through my mnemonics for remembering all four of the fat soluble vitamins using a really catchy memory hook we'll go through some normal physiology and things like that but this is mostly gonna be focused on what you need to know for USMLE and comlex specifically and I'm gonna leave out all of the other minor details that you should consult your biochemistry textbook for if you're interested in learning more so let's jump right into it so the first thing that you need to do is remember what the four fat soluble vitamins are so with that in mind how do we remember that vitamins D K and E are the four fat soluble vitamins well you need to ask yourself who is somebody who takes their vitamins specifically who is somebody who takes their fat soluble vitamins to stay really healthy and perform smash rap music that of course is gonna be Drake so this is the mnemonic D a ke with the little R because R vitamin R is obviously not a vitamin but vitamin D vitamin A vitamin K and vitamin E are the fat soluble vitamins and if you want to be a multi-billion dollar rap artist you better damn well take your fat soluble vitamins so Drake is how we're going to remember this so we're gonna go through these one at a time in order obviously skipping our because it's not a fat soluble vitamin so let's start with the first vitamin vitamin D so with vitamin D you basically need to know that it's overall function in the body is to increase the level of calcium now it does this by acting on three different sites and conveniently the mnemonic is going to be the letter D so the first one that you see here is that vitamin D increases the absorption of calcium in the distal renal tubular right so it increases the absorption of calcium that's the vitamin D job this is the first site where it does that in the distal renal tubular the second site which you see here again with the other red D in the red arrow is that vitamin D increases the resorption of calcium in the duodenum so so far we have distal renal tubular and both of them conveniently begin with the letter D and that's where vitamin D has its action the last one where vitamin D acts which you see here kind of pointing to the bone in the hand is that it destroys bone so destroy begins with D and destroy bone that is to say that vitamin D activates osteoclasts and osteoclasts our bone resorption cells so bone resorption or destroying them therefore releasing calcium from the matrix of the bone so vitamin D acts in the distal renal tubular the duodenum and it destroys bone all of those things start with the letter D remember that with a destroying bone we're saying that vitamin D activates osteoclasts and of course osteoclasts our bone resorbs okay so that's how vitamin D increases calcium it does it in three different areas this is very high-yield you need to know all three of these the next thing that you need to know that there are different types of vitamin D whether it's active latent where in the body it is so let's pause for a second so in vitamin D you obviously everybody knows you you get some from the Sun that's not really high yield but it you know it shows up from time to time you get it from the Sun you can get it from your diet but the ability to move vitamin D throughout your body through different organs and changing its molecular type to activate it is really really high yield and for whatever reason students really struggle with this there's never been a good explanation for how you remember which chemical formula is active in which part of the body and where it's stored and where it's activated so I'm gonna demystify this right now so vitamin D comes in two flavors there's 25 hydroxy d3 and then there's 1 comma 25 and then in parentheses it's 2 of the Oh H groups d3 now these are two different forms of vitamin D right one is where vitamin D gets stored it's storage form and the other is where it gets activated for peripheral use so the 2500hd 3 is what you find in the liver and that's mostly where it's stored the 125 o h 2 d 3 the other form of vitamin d that's in the kidney and that's where vitamin d really gets activated to exert its utmost effect on calcium so how do you remember which ones which which ones active and whether it's in the liver of the kidney well the mnemonic here is oh the liver is where it lies but the kidneys 125 oh the liver is where it lies but the kidneys 125 so let's kind of go through this so Oh the liver is where it lies tells us that the one with 100 or 100 H the liver it's in the liver is where it lies which is to say that's where it is stored but the kidneys 125 so by the process of elimination oh the liver is where it lies so the one with 100 H in the liver where it lies or where it's stored but the kidneys 125 so in the kidney it's the 125 version and by process of elimination since you know that oh the liver so the liver is the one with the one o H the one with the two O H's that's 125 that's in the kidney and because the liver is where it lies the kidney is where it's active so in the kidney you get the activated form so this mnemonic tells you everything you need to know about this seemingly confusing topic and it's really not that bad but it is super high-yield because for whatever reason examiner's love to ask you which form of vitamin D you have in which organ and whether it's a storage form the activated form all that crap so no this no this pneumonic it will take you really really far very briefly not too much clinically to know about vitamin D if you have a deficiency in vitamin D it manifests as two different disease processes depending if you're a child or if you're a grown adult so in children it causes rickets in adults it causes osteomalacia if you see a picture that looks like this with bowing of the knees the answer is vitamin D deficiency and I always remember that because the one bowing of the knee kind of looks like the part of the D that's curved I don't know maybe it doesn't see you but it always did to me so that's vitamin D remember the mnemonic and remember the different forms where it's active where it's stored and remember the three sites in the body where vitamin D exerts its effects in the distal renal tubules in the duodenum and by destroying bone very easy to remember let's move on to vitamin A so Drake is our rap superstar who takes his vitamins to stay healthy so he can do all his shows on the road so D we did there's obviously no vitamin R so now we're on vitamin A so vitamin A has some things that you need to know and just like with vitamin D we use the letter DS with vitamin A we're gonna use the letter A s so the first is that it's an antioxidant and specifically its antioxidant ability is manifested by it being used to treat measles and for it being used to treat retina pigmentosa so it is an antioxidant very useful in the treatment of measles and in the treatment of retinitis pigmentosa know that those are both very high yield facts but vitamin A first we start with a four antioxidant now we're gonna talk about a four aura so aura aka the ability to see light if you have a vitamin A deficiency you get something called night blindness so vitamin A helps us with our vision specifically the ability to see the light so a four aura a four antioxidant the next thing is a for activation so vitamin A causes epithelial cells to differentiate into various different cell subtypes so a for activation specifically for epithelial cells differentiating the last two things that I want to throw in by using the letter A is a for alopecia and a for abnormal pregnancy so too much vitamin A vitamin A and excess can cause alopecia and it can cause abnormal pregnancy which is to say that it causes birth defects so you really have to make sure that you're taking the right amount of vitamin A or else you can have adverse effects so vitamin A for antioxidant or the ability to see light activation epithelial cells differentiating and too much vitamin A causes alopecia and birth defects aka abnormal pregnancy so that's a vitamin A moving right along Drake needs to keep taking his fat soluble vitamins he's taking vitamin D there is no vitamin r he's taking vitamin A and now we're gonna talk about vitamin K so keeping with our theme of using the letter in the vitamin K there are three things that you need to know one is that vitamin K is used to form clotting factors specifically 2 7 9 10 protein C and protein s so if you know anything about how coumadin aka warfarin works warfarin or coumadin the the the same thing the generic and the brand name that drug inhibits factors 2 9 7 10 protein C and protein s so if vitamin K is used to make these clotting factors then vitamin K gets crushed by warfarin so the mechanism of warfarin is that it inhibits vitamins K's ability to make clotting factors so super high yield you need to know that so vitamin K is in green leafy vegetables another really really high you look fact I always remember the vitamin K is in kale k al e remember that it's in leafy vegetables remember that it's used to make clotting factors 2 7 9 10 C ns and that it's crushed or inhibited by boyfriend kind of going off that it's really high yield to know the mechanism of how vitamin K is used to make these clotting factors so vitamin K is a cofactor of gamma carboxylation that is the mechanism with how it makes the clotting factors so remember both of those things they kind of go hand in hand the last really really high yield points to know about vitamin K is to know that vitamin K does not is not in breast milk so when you have a newborn if you're breastfeeding the newborn is gonna need vitamin K which is normally in the gut flora so vitamin K is not made by the nipples that's how I remember that so use the letter the letter K with the n after it's are not made by the nipples it's a clotting factor that's crushed by warfarin and the mechanism is that it's a cofactor of gamma carboxylation very high-yield points vitamin K is so high-yield people really underestimate how often it shows up on exams please know these facts moving right along we're gonna wrap up by talking about vitamin E so remember drake takes his fat soluble vitamins now we're talking about vitamin E and vitamin E is the simplest vitamin to have to memorize of these four there's the least amount of information about it it doesn't show up too too often the only thing you need to know about vitamin E is that it's an antioxidant so it's an antioxidant vitamin E is an antioxidant specifically prevents the peroxidation of fatty acids so it is protective against arteriosclerosis if you can remember these very very minor points you'll pretty much be able to answer any question that they throw at you concerning vitamin E but guys that's it if you were able to follow along with this video memorize the mnemonics and everything made sense that you are now a master a fat soluble vitamins shout-out to Drake