Vitamin B12
Vitamin B12 is also called cobalamin because it contains the metal cobalt. This vitamin helps maintain healthy nerve cells and red blood cells. It is also needed to help make DNA, the genetic material in all cells.
Vitamin B12 is bound to the protein in food. Hydrochloric acid in the stomach releases B12 from proteins in foods during digestion. Once released, vitamin B12 combines with a substance called gastric intrinsic factor. This complex can then be absorbed by the intestinal tract.
Vitamin B12 is naturally found in animal foods including fish (trout, salmon, haddock, clams, tuna), meat (beef, pork), poultry (chicken breast), eggs, milk, and milk products. Fortified breakfast cereals are a particularly valuable source of vitamin B12 for vegetarians.
Results of two national surveys, the National Health and Nutrition Examination Survey and the Continuing Survey of Food Intakes by Individuals found that most children and adults in the United States (U.S.) consume recommended amounts of vitamin B12. A deficiency may still occur as a result of an inability to absorb B12 from food and in strict vegetarians who do not consume any animal foods. As a general rule, most individuals who develop a vitamin B12 deficiency have an underlying stomach or intestinal disorder that limits the absorption of vitamin B12.
According to the U.S. Food and Drug Administration, B12 is beneficial in people over age 50 who often have a reduced ability to absorb naturally occurring vitamin B12.
