Vitamin B12, also known as cyanocobalamin, is essential for the body's growth, blood formation, reproduction of cells and synthesis of proteins and tissues, Drugs.com states. Vitamin B12 is sometimes used to treat people who have anemia.
Vitamin B12 functions in red blood cell formation by binding to food during the digestive process when gastric acids are released, explains the National Institutes of Health. Next, vitamin B12 combines with the substance known as intrinsic factor before being absorbed into the bloodstream.
The average healthy person has enough vitamin B12 stored in the liver to last several years. A condition known as pernicious anemia, however, makes the body unable to absorb vitamin B12 from the intestines, resulting in a lack of the vitamin, states Mayo Clinic. People with this condition require regular lifelong doses of vitamin B12 in order to keep normal levels. Those who have symptoms of anemia caused by a vitamin B12 deficiency can benefit from a one-time vitamin B12 treatment to get their levels back to normal.
Vegetarians or people who don't eat a wide enough variety of foods are susceptible to a vitamin B12 deficiency and benefit from a daily dose of the vitamin. Drinking alcohol and taking certain medicines also can lead to a vitamin B12 deficiency.