Vitamin B-12 (cyanocobalamin) is a water soluble vitamin necessary for the maintenance of a healthy nervous system and for the production of energy from fats and proteins. Vitamin B-12 is also essential for the synthesis of DNA during cell division and therefore is especially important for rapidly multiplying cells, such as blood cells.

In addition, adequate intake of vitamin B-12, along with folic acid and vitamin B-6, is critical for the conversion of homocysteine to methionine, thereby supporting a healthy cardiovascular system. While B-12 is stored in the liver, dietary sources are of animal origin only (meat and dairy). Therefore, supplementation with B-12 may be especially important for strict vegetarians.