Vitamin B12 is an essential vitamin that is found in many common foods such as fish, meat and dairy products. In addition, many people take vitamin B12 as part of a vitamin B complex in a dietary supplement.

Dosage

The recommended daily allowance for vitamin B12 varies with age and other health factors. 2.4 micrograms is recommended for adults over age 14 and pregnant or lactating women need 2.6 micrograms and 2.8 micrograms, respectively. As people age, they have a harder time absorbing the vitamin from food and may need to take a supplement to maintain healthy levels. The vitamin can be supplemented through oral, intranasal or intramuscular means.

Benefits

Vitamin B12 is necessary to the body because it helps maintain nerve and red blood cells and contributes to the creation of DNA. The vitamin has also been noted to increase energy levels and help prevent heart disease and thrombosis.

Deficiency

The body stores the vitamin for years, so deficiency is very unlikely. However, elderly people may have trouble absorbing the vitamin, and some people have an inability to absorb it. The major symtoms of a deficiency revolve around neurological and psychiatric problems. Shaky movements, muscle weakness, low blood pressure, vision problems, dementia and mood disturbances are all linked to a deficiency. In addition, two types of anemia, megaloblastic anemia and pernicious anemia, are linked to a deficiency. Megaloblastic anemia is a condition distinguished by red blood cells that are larger than normal and pernicious anemia is another type of blood abnormality. Researchers have noted that these problems can begin to occur when the vitamin levels are only slightly below normal. However, anemia is usually associated with significantly lower levels than the other health problems described.