Nutrition: Introduction to Vitamins – Genetics | Lecturio

Nutrition: Introduction to Vitamins – Genetics | Lecturio

September 26, 2019 5 By Ewald Bahringer


[Music] in this first lecture on vitamins I’ll be introducing you to differences between water soluble and fat soluble vitamins and then we will go on to explore the details of each that you should know for your exams first we’ll take a look at the common features of water soluble vitamins first of all they are hydrophilic hence the reason that they are water soluble which means that we need them only in small amounts and that any excess is going to be excreted in the urine so rarely will we see a toxicity of water soluble vitamins but more likely a deficiency because there are no backup stores in the body the exception to this rule are in vitamin b12 and b9 which are stored in a fairly significant amount in the liver so that they are available for future use so let’s take a quick look at all of the vitamins water soluble vitamins that we’ll be covering this is all the B’s as well as the vitamin C and you have names associated with each but let me caution you or let you know that these names and numbers are not things that you need to match together anytime they mention on your exam one or the other both pieces will be there of course by the time you are done with learning these specimens you probably will know the names as well as the letters associated with them for each anyway we will then cover details of fat soluble vitamins fat soluble vitamins there are many less of them so much less to handle there they are all hydrophobic and hence the fact that they are fat soluble again necessary in small amounts any excess here will be stored in the liver or fat because they are stored in the liver or fats we can actually experience toxicities with fat soluble vitamins but deficiencies are much less common because there’s generally three to six months worth of storage in the fat and liver tissues so water soluble vitamins water soluble fat soluble vitamins fat soluble simple enough right here’s how I remember my fat soluble vitamins you can either remember that they are all of the vitamins that are not B and C or you can remember them as a ke and D again the names are always going to be associated with the letters in the case of fat soluble vitamins the actual name can change dependent on the form of the particular vitamin for example we might have vitamin d2 or d3 d3 is the cholecalciferol and the way that I remember these is by imagining a big fat lady laying on the beach naked so and we add that in there and then aka e and D and I can sort those out pretty good visual to keep that in mind we use that with students it seems to work so big fat lady laying on the beach stuff an N in front of it and you’ve got or naked fat lady laying on the beach cannot include a picture here so that’s all good I’m sure you will keep that in your memory now the key here with absorption for fat soluble vitamins is they are fat soluble and so they are generally going to be bound up in fats which means that we require pancreatic enzymes in order to absorb them right they’re absorbed very chylomicrons in the small intestines so any disorder that interferes with pancreatic enzymes will create issues with absorption of fat soluble vitamins now if you have a decrease in fat absorption clearly as recovered you’ll have a decrease in fat soluble vitamin absorption also if you have a decrease in that absorption one of the main symptoms is guess what well one of the main symptoms is steatorrhea maybe you haven’t heard that word maybe you have but that ends up meaning basically greasy stools so fat in the stool steatorrhea can result or can be a good indicator that someone may have problems with the pancreas or fat absorption and or and potentially fat soluble vitamin absorption so oily stool smells really bad bad symptom to have anyway many of the causes of steatorrhea are here in the table as you can see most of them relate to issues with the pancreas or for example with Crohn’s disease and celiac disease absorption across the intestine so cystic fibrosis it comes up because with cystic fibrosis we have decrease in in fluids so we have the stickiness which actually inhibits the secretion of pancreatic enzymes so that’s one of the symptoms also of cystic fibrosis is decrease in fat absorption and so keep in mind that anywhere we’re talking about absorption issues we could have a problem with any of the vitamins but particularly any issues of the pancreas we can have an issue with absorption of fat soluble vitamins so on that note I’d like to share with you an interesting situation you can see in the above image that fat digestion occurs normally using the enzyme lipase right secreted from the pancreas and it breaks the fatty acid chains away there are a number of drugs on the market presently for prescribed and over the counter for weight loss that all fall under the umbrella of orlistat now what orlistat does is theoretically cuts the amount of fat absorbed in and so we see that it interferes with the lipase enzyme and leaves the fats intact or triglycerides intact and I bet that you can guess what one of the major side effects of drugs like a lie or or Lestat’s are well yeah you’ve got it stay at area not such a great symptom and whether they’re effective or not potentially they are if you see the patients are having increased levels of exercise and reduced caloric intake so they should definitely be prescribed with lifestyle modifications also so in short this was a very brief introduction to the differences between fat soluble and water soluble vitamins and I look forward to seeing you in the next series of lectures as we highlight all the aspects that you need to know for your exams [Music] you