Term coined in 1911 (vita, Latin word for life, and the chemical term amine) by polish biochemist, Casimir Funk, represents one of a group of organic substances, some of which are of unknown composition, present in minute amount in natural foodstuffs which are essential to normal metabolism. A lack of vitamins in the diet causes deficiency diseases.Vitamins are commonly classified into two groups, the fat-soluble, and the water-soluble. Vitamins A, D, E, and K are fat-soluble. Vitamin C and members of the vitamin B complex group are water-soluble. In general, the vitamins play catalytic and regulatory roles in the body’s metabolism. Among the water-soluble vitamins, the B vitamins apparently function as coenzymes. Vitamin’s C coenzyme role, if any, has not been established. Part of the importance of vitamin C to the body may result from its strong antioxidant action. The actions of the fat-soluble vitamins are less well understood. Some of them, too, may contribute to enzyme activity, and some of them are essential to the functioning of cellular membranes.