Vitamin B-12 plays an important role in blood formation. It is needed to form red blood cells in the bold and preventing anemia.

Together with folic acid and vitamin B6, vitamin B12 has been shown to reduce high plasma levels of homocysteine, which is an independent risk factor for cardiovascular disease.

Vitamin B12 also prevents nerve damage, and promotes normal growth and development by maintaining the fatty sheaths (myelin sheath) that cover and protect the nerve endings.

This vitamin also is essential for proper digestion, absorption of foods, the synthesis of protein, and the metabolism of carbohydrates and fats.

Vitamin B12 deficiency can be caused by malabsorption, which is most common in elderly persons and those with digestive disorders. Classic deficiency of B-12 is pernicious anemia in which the signs are weight loss, weakness, pale skin and psychological distrubances. Strict vegetarians should remember that they require Vitamin B12 supplementation. Although people adopting a strictly vegetarian diet may not see any signs of B12 deficiency for some time.