Fat Soluable Vitamins

Fat Soluable Vitamins - Introduction There are a large...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Introduction There are a large number of vitamins. All of the known vitamins will be listed and discussed. Some will receive much more attention than others. These are the ones that I consider most likely to be problematic. They are all important. If you do not consume or otherwise obtain one of the vitamins you will die. For some vitamins this is almost impossible if you eat any food at all. Some vitamins are very widespread and the likelihood of developing a deficiency is very low. These vitamins will be included for completeness, but there will be limited discussion of them. These vitamins are unlikely to appear on an exam. You do not need to know sources of vitamins or RDAs. If there is a deficiency disease you should be able to associate the disease with the vitamin. Vitamins can be divided into those that are soluble in fat and those that are soluble in water. Vitamins Vitamins are organic compounds Required in trace amounts Perform specific metabolic functions Not synthesized by the body or not synthesized in adequate amounts The properties listed above are true for all vitamins. Traditionally vitamins were discovered by removing substances from the diets of animals until a disease state occurred. The addition of the substance back to the diet was checked to see if the disease was cured. If it was the substance was considered a vitamin. Much of this work was done between 1915 and 1945. On several occasions more than one substance was removed. Many times different groups discovered the same vitamin but gave it different names. Over time these problems were sorted out and today we have a good idea of what substances are vitamins. We also know what their metabolic role is in the body. If a substance is not required for some metabolic function it is not a vitamin. A number of such compounds are touted as good for health. Some of them may be, but they are not vitamins. Often as these compounds are studied it is found that they have minimal if any affect on health. We will deal with those that are known to be essential. Fat Soluble Vitamins All have similar mechanism of absorption and excretion Do not have to be consumed daily Excess can be toxic Relatively stable during processing Vitamin A Occurs in pre formed state and as a precursor Three active forms: Retinol Retinal
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Retinoic acid In food most pre formed vitamin A is found in the form of retinal It is important to recognize that Vitamin A can come from animal or plant sources. Animal sources of vitamin A have activity while the -carotene from plants is only active after conversion in the liver. If the Vitamin A content of the liver is high the -carotene will not be converted to an active form. Excess Vitamin A can be toxic. Excess β -carotene is not toxic because it will not be converted to Vitamin A unless there is a deficiency. Vitamin A
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 13

Fat Soluable Vitamins - Introduction There are a large...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online