Vitamins may be defined as – various fat/water-soluble organic substances that are essential in minute amounts for normal metabolic function.

  Vitamins may be defined as – various fat/water-soluble organic substances that are essential in minute amounts for normal metabolic function. Vitamins are synthesised by bacteria and plants but are obtained by animals chiefly in their diet. Describe the structure and functions of the common vitamins (A, B complex, C, D, E and K) in the human diet. Your response should include reference to the classification of vitamins, principle sources, associated deficiency diseases and toxic effects." include details of pre cursors and chemical compounds of at least two of the vitamins - Preferably one fat and one water soluble