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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). |