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usually administered as nutraceutical or functional ingredient. They are classified as
either water-soluble or fat-soluble (Figs 11.1a, b). The water-soluble vitamin group
includes thiamine and its derivatives, vitamin B 1 , riboflavin (vitamin B 2 ), niacin
(nicotinic acid) and its amide (nicotinamide, vitamin PP), vitamin B6 vitamers (pyridoxal, pyridoxine, and pyridoxamine and their derivatives), pantothenic acid, folic
acid and its derivatives (folacin), biotin (vitamin H), and cyanocobalamin (vitamin
B 12 ), in addition to L-ascorbic acid and L-dehydroascorbic acid (vitamin C) and
other biologically active compounds, classified as pseudo-vitamins, such as orotic
acid (vitamin B 13 ), 4-aminobenzoic acid, inositol (myo- and meso-inositol), rutin
(vitamin P), and S-methylmethionine (vitamin U). The fat-soluble vitamins fall into
four groups of vitamin-active compounds: vitamin A (retinoids and carotenoids),
vitamin D [ergocalciferol (D 2 ) and cholecalciferol (D 3 )], vitamin E (tocopherols and
Fig. 11.1 (a) Structures of some water-soluble vitamins. (b) Structures of some fat-soluble
vitamins
11 Chemical Composition and Nutritional Properties of Functional Food