Vitamin B-12 is a chemically complex substance that plays a central role in producing red blood cells and regulating nerve cell function. Like other B vitamins, vitamin B-12 also assists with energy metabolism. Vitamin B-12 is water-soluble but, unlike other water-soluble vitamins, the body can store vitamin B-12 in the liver for several years. Vitamin B-12 intake needs to progressively increase throughout your life.
Infants
Recommended dietary allowances are set by the Institute of Medicine. While the IOM provides RDAs for vitamin B-12 for older age groups, there is still insufficient dosage evidence for infants. Instead, the IOM provides an adequate intake dosage, or an amount that is believed to support infant nutritional needs. The AI for infants ages 0 to 6 months is 0.4 mcg per day, while infants ages 6 months to 1 year need 0.5 mcg of vitamin B-12 each day.
Children
Boys and girls need about the same amount of vitamin B-12 both before and after puberty. The RDA for all children ages 1 to 3 is 0.9 mcg each day. As children get older, they need slightly more, with the RDA set at 1.2 mcg per day for children ages 4 to 8 years.
Adolescents and Adults
Males and females ages 9 to 13 need about 1.8 mcg of vitamin B-12 each day. From then on, males and females need 400 mcg per day. After about the age of 50, however, adults begin to have a difficult time absorbing food-bound vitamin B. The IOM recommends adults over this age consume most of their vitamin B through fortified foods or supplements.
Nursing Mothers
Nursing and pregnant mothers need additional vitamin B-12 beyond that of non-nursing and non-pregnant women. Pregnant women, regardless of age, need about 2.6 mcg of vitamin B-12 each day. Nursing mothers need more still, with the RDA set at 2.8 mcg a day for nursing mothers of all ages.
Sources
You can find an abundance of vitamin B-12 in red meat, fish and dairy products. Other seafood products, such as clams and mussels are high in vitamin B-12 as well. You can find vitamin B-12 in supplement form by itself, as part of a vitamin B complex or as part of a general multivitamin. Vitamin B-12 is also available by prescription as an injection or nasal gel.
References
- Linus Pauling Institute at Oregon State University: Vitamin B-12; Jane Higdon; 2003
- University of Maryland Medical Center: Vitamin B-12
- Institute of Medicine: Dietary Reference Intakes; Recommended Dietary Allowances and Adequate Intakes; Vitamins; 2005
- Kids Health: Vitamins and Minerals; October 2009
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