Vitamin B12(Cobalamin)

Vitamin B12, or cobalamin, is naturally found in animal foods. It can also be added to foods or supplements. Vitamin B12 is needed to form red blood cells and DNA. It is also a key player in the function and development of brain and nerve cells. Vitamin B12 binds to the protein in the foods we eat. In the stomach, hydrochloric acid and enzymes unbind vitamin B12 into its free form. From there, vitamin B12 combines with a protein called intrinsic factor so that it can be absorbed further down in the small intestine. Supplements and fortified foods contain B12 in its free form, so they may be more easily absorbed. There is a variety of vitamin B12 supplements available. Although there are claims that certain forms—like sublingual tablets or liquids placed under the tongue to be absorbed through the tissues of the mouth—have better absorption than traditional tablets, studies have not shown an important difference. Vitamin B12 tablets are available in high dosages far above the recommended dietary allowance, but these high amounts are not necessarily the amount that will be absorbed because an adequate amount of intrinsic factor is also needed. In cases of severe vitamin B12 deficiency due to inadequate intrinsic factor (pernicious anemia), doctors may prescribe B12 injections in the muscle.