I'm attempting to study for my nutrition test in the morning...it is all on vitamin functions and deficiencies. To help me study I am going to post some information here (I'm dragging you into my college study session!).
Okay here we go:
First up are the fat soluble vitamins. Their storage capacity is significant and deficiencies may not immediately occur. Their absorption is very similar to that of lipids and triacyglycerol.
Vitamin A is high in carotene and pure forms of it can be found in animal sources such as liver, milk, eggs, etc. Supplemental vitamin A is generally sold in a dry, gelatin coated form to which antioxidants have been added. Because vitamin A is extremely susceptible to oxidation, the gelatin coating and antioxidants prevent complete destruction. It is good for your night vision and healthy epithelial cells and is also important in glycoprotein synthesis.
Vitamin D can be acquired from UV light with the exception of fish. D2 comes from plant sources, while D3 comes from animal sources. Poultry and fish poorly utilize D2, so their diets must be supplemented with D3. Vitamin D is important for the mobilization, transport, absorbtion, and use of Ca (Calcium) and P(Phosphorous). Deficiencies include disturbance of Ca and P absorption, rickets in young animals, osteoporosis in adult animals due to decreased mineral content of the bones, and milk fever in cows, because calcium requirements were not met immediately following parturition (calving).
Vitamin E can be acquired through vegetable oils and supplements. It is important for normal reproductive functions (both male and female), is a biological antioxidant, which can be defined as a mutual sparing effect, which basically means that a deficiency in Vitamin E can reduce the absorption of other vitamins and minerals (such as selenium). Deficiencies include muscle degeneration, anemia, liver problems, digestive disorders, impaired immune function, and even sudden death.
Vitamin K is formed from bacterial synthesis in the gastrointestinal tract of animals, but the amount synthesized does not generally meet the requirement, especially in monogastrics. Vitamin K is used in the body's blood clotting mechanism, so deficiencies can include reduced ability to form clots, which can then result in unchecked internal hemorrhages. Antibiotic therapy can also result in a Vitamin K deficiency.
The other kind of vitamins are known as water soluble. I only know about the B complex series, and there's a lot of them, so I won't go through them here. The interesting thing is though, that ruminant diets do not need to be supplemented with B complex vitamins, because the microorganisms that inhabit the digestive tract of ruminant animals have the ability to synthesize enough to meet the requirement for the animal. Monogastrics almost always need some form of supplementation in their diets. Pretty cool, huh?
Whew, see that wasn't so bad, was it? And now you are all kinds more smarter and know what to look for when you are deficient in certain vitamins.
--L
P.S. Humans are monogastrics. :)