Definition: A vitamin that is used for several body functions including metabolism, the maintenance of the central nervous system, and the creation of red blood cells. Vitamin B12 is one of the water-soluble vitamins and is excreted through urine if it is not used by the body. Food sources of vitamin B12 include eggs, meat, poultry, shellfish, and milk. A lack of B12 can leave the body unable to make more red blood cells, which can result in symptoms such as weakness, tingling in the arms and legs, or a condition called pernicious anemia.
Vitamin B12 is absorbed in the small intestine, and people who have had surgery to remove sections of small intestine (such as people who have Crohn's disease) may not be able to absorb enough B12. A lack of vitamin B12 is treated by supplementation, such as by receiving B12 shots on a regular basis.
The recommended daily amounts of vitamin B12, in micrograms, are:
- Infants aged 0 - 6 months: 0.4 mcg
- Infants aged 7 - 12 months: 0.5 mcg
- Children aged 1 - 3 years: 0.9 mcg
- Children aged 4 - 8 years: 1.2 mcg
- Children aged 9 - 13 years: 1.8 mcg
- Men and women aged 14 years and older: 2.4 mcg
Alternate Spellings: Vitamin B-12, Vitamin B 12
