Vitamins are low molecular weight organic compounds indispensable for the normal activity of the organisms. Their absence causes deficiency symptoms. Most of the vitamins or their derivatives are coenzymes which are essential for many important enzymatic reactions in the cells.
Vitamins are required in small quantities for a variety of biochemical functions in our body. Most of them cannot be synthesised by the body and must be supplied through the diet. Unlike carbobydrates and lipids, they are not metabolised for providing energy. Normally, a well balanced diet will supply all the necessary vitamins in sufficient quantities.
Vitamins are broadly classified into two groups based on their solubility.
i. Fat soluble vitamins
Vitamins A, D, E and K
ii. Water soluble vitamins
Vitamins B (B1, B2, B3, B6 & B12), Biotin, Folic acid, Pantothenic acid and C