**14. Vitamins**

Vitamins are organic molecules and essential for the proper functioning of the human body. Vitamins are required in small amounts obtained from a correct diet. There are two types of vitamins such as fat-soluble vitamins and water-soluble vitamins. Fat-soluble vitamins are A, D, E, and K and they can be stored in the body. On the other hand, water-soluble vitamins are C and B-complex, such as vitamins B6, B12, niacin (B3), riboflavin (B2), biotin (B7), thiamine (B1), pantothenic acid (B5), and folic acid (B9). They cannot be stored in the body because the excess ingested is eliminated through human fluids, such as urine and transpiration, and hence necessary to ingest a daily amount of these vitamins [106].
