Vitamin B-12, or cobalamin, is a member of the water-soluble family of B-complex vitamins. It's required for normal function of nerve cells, DNA production and your body need vitamin B-12 to make an adequate number of blood cells.
1 to 3 years: 0.9 microgram per day
4 to 8 years: 1.2 micrograms per day
9 to 13 years: 1.8 micrograms per day
14+ years: 2.4 micrograms per day
Vitamin B-12 is found naturally in meats, poultry, seafood, eggs, and dairy products -- foods that are high in protein. Supplementation should not be necessary for healthy adults, except for vegans, as vitamin B-12 is only found in animal products. Ovolactovegetarians will get vitamin B-12 from eggs or dairy products.
Taking vitamin B-12 supplements will reduce homocysteine levels in your blood. Unfortunately, taking the supplements doesn't appear to reduce your risk of cardiovascular disease.
Vitamin B-12 supplements have also been recommended for improving cognitive skills, and to boost energy. But research hasn't provided sufficient evidence for these recommendations.
Also Known As: Cobalamin
"Vitamin B12." Accessed March 17, 2009. http://ods.od.nih.gov/factsheets/vitaminb12/.Otten JJ, Hellwig JP, Meyers LD. "Dietary Reference Intakes: The Essential Guide to Nutrient Requirements." IOM, 2006.