Optimal Treatment For Vitamin B12 Deficiency

Although vitamin B-12 is one of the B complex vitamins, it differs from the other B vitamins in several respects. It is the only that contains an essential mineral -- cobalt -- which is why vitamin B-12 is also called cobalamin. The absorption of food-based vitamin B-12 requires the presence of a protein called intrinsic factor, which is secreted from the acid-producing cells in your stomach. Unlike the other B vitamins, B-12 is stored in your liver for many months. Thus, deficiencies develop slowly and insidiously.

Absorption

Vitamin B-12's mechanism of absorption carries implications for treating its deficiencies. B-12 is separated from foods by the action of acid and digestive enzymes in your stomach. Free B-12 binds to gastric "R proteins," which protect the B-12 until it is carried into your small intestine, where pancreatic enzymes split the vitamin B12-R protein complex apart. B-12 then binds to intrinsic factor, which has also passed into the small intestine from your stomach. This intrinsic factor-vitamin B-12 complex is finally absorbed through the wall of your lower small intestine.

Deficiency

Vitamin B-12 deficiency is usually due to inadequate intake or poor absorption, notes the USDA. Due to your liver's capacity to store B-12 for extended periods of time, you might not develop a deficiency for months or even years following a decline in B-12 consumption or absorption. Eventually, though, B-12 deficiency causes megaloblastic anemia, which is characterized by abnormally large, poorly functioning red blood cells. If B-12 deficiency remains untreated, potentially irreversible nerve damage can occur. The optimal treatment of B-12 deficiency depends on its severity.

Treatment

According to "The Merck Manual of Diagnosis and Therapy," vitamin B-12 deficiency can be treated with large oral doses -- 1,000 to 2,000 micrograms daily -- if you do not have neurological symptoms. Sublingual formulations can also be used in such cases. Oral and sublingual preparations, which contain crystalline B-12, can be absorbed even if you do not produce intrinsic factor. If you do have neurological symptoms, such as numbness, confusion, poor balance or dementia, doctors typically administer 1 mg of injectable B-12 up to 4 times weekly for several weeks, and then once monthly until neurological symptoms resolve. In most cases, oral or sublingual treatment is then continued for life.

Considerations and Recommendations

Vitamin B-12 is only found in appreciable amounts in animal-based foods. B-12 deficiency is more common among strict vegans who do not consume animal foods and among the elderly, whose absorption of vitamin B12 is often inadequate. Daily requirements for vitamin B-12 range from .4 micrograms for infants to 2.8 micrograms for lactating females. Oral doses of 2,000 micrograms or more are often used without ill effects.