Vitamin B12

Vitamin B12 is involved in many body processes, including the synthesis of DNA, red blood cells and the myelin sheath that surrounds nerve cells and conducts nerve signals. The stomach secretes intrinsic factor, a special digestive secretion, to help the small intestine better absorb vitamin B12 from food.*

Like folic acid, vitamin B12 acts as a methyl donor to other molecules. It plays a critical role in energy metabolism, immune function and nerve function.*

Poor dietary intake and lack of intrinsic factor in the stomach can lead to deficiency, which can cause a host of health problems.* Vitamin B12 is found only in animal foods. That's why it's important for those on a vegetarian, vegan or macrobiotic diet to take supplemental B12.*

Unlike other water-soluble vitamins, vitamin B12 is stored in the liver, kidney and other body tissues. Because of this, signs and symptoms of deficiency may not appear for many years.* 

Studies indicate that the level of vitamin B12 declines with age.*