Vitamins are a group of organic nutrients, which are essential to regulate the chemical processes that go on in the body. Generally speaking vitamins cannot be made in the body and must be obtained from foods, or supplements.
There are two main groups of vitamins. Fat-soluble vitamins such as vitamins A, D and E which can be dissolved in fat and can be stored in the body and water-soluble vitamins which include the B vitamins and vitamin C, that dissolve in water and are not stored in the body. Consequently, water-soluble vitamins need to be replenished on a daily basis.