الفهرس 
Fat soluble vitaminsrOnly 14 pages are availabe for public view
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Abstract
Vitamins aTe oTganic ~ub5tan~es 0, groups of .elated
substances I found in some foods, cofactors for the
enzyme (5) of some metaboli.c step (5 J in the human body,
not made in the body, and required in very small amounts,
(lruswell. 19a5).
Vitamins ere usua.llyclllssified according to so Iubf.-
l’ity into two group’s. ihe ht-soluble group includes
i~amin5 A, D. B, and K. Tbe water-soluble group includes
Vitamin C and the B-Complex Vitamins. The B-Complex
Vitamins include ~hiamine {Vitamin 811• riboflavin
(Vitamiri B2). niacin (nicotinic acid), pyridoxine
(Vitamin BIj), pantoth,enic·acidl, biotin, folic aci d
(folacin), cobalamin (Vitamin B12), lipoic acid, pa~a
amino-benzoic acid. inositol and choline (~illiams,
981).
Requirement~ for Vitamins vary considerably according
to circumstances. As the carbohydrate content of
the diet increases, the requirements fOT thiamine increase.
As protein content of the diet increases, requirements
for Vitamin B6 increase and requirements faT niacin and
pantotheni~acid decrease. Incre~sed dietary intake of
polyunsaturated fatty acids results in ”ncTeased requirements
for Vitamin E. lofcth.ioninQ may have a sparin.g ~£fect.
with respect to requ:iTement for fOlacin and Vitam’”n 812.
TD’ptophan can replace part of the dietary reqUirement
for niacin. Abundant evidence indicate~ that composition
of the diet influences sYDt~esis of B·vitamins by miCrOorganisms
of the gastrointestinal tract (Gershoff. 1964).