Vitamins – are organic nutrients that do not provide calories for energy. They are needed in the diet in tiny amounts. Vitamins in foods come in the form of precursors (forerunners), also known as provitamins. Precursors are intermediate enzymatic reactive compounds that can be converted into active vitamins. Once eaten, the body changes them chemically into active vitamins. Vitamins do not make you strong nor do they provide you with energy. However, they help other nutrients do their work properly. For example, Vitamin B1 called Thiamin helps in the breakdown of carbohydrate for energy.