Vitamin B12, a water soluble Vitamin, is a part of the Vitamin B complex and is the most complicated vitamin structurally and chemically. It is also known as cobalamin as it contains the biochemically rare element cobalt. Cyanocobalamin, a common synthetic form of Vitamin B12 is used in food additives and nutritional supplements. Methylcobalamin and 5-deoxyadenosylcobalamin are the forms of vitamin B12 that are active in human metabolism.