Vitamins may be defined as the chemicals that are required in diet in the small amount. The deficiency of the vitamins may cause the characteristics disease in the individual.
Two main types of vitamin are fat soluble vitamin and water soluble vitamin. The vitamin B12 is the water soluble vitamin that requires some instrinsic factors for its absorption. This vitamin is also involved in the functioning of the nervous system. The deficiency of this vitamin may cause pernicious anemia.
