The best way to meet your body's vitamin B12 needs is to eat a wide variety of animal products.
Supplemental vitamin B12 can be found in the following:
Almost all multivitamins. Vitamin B12 is better absorbed by the body when it is taken along with other B vitamins, such as niacin, riboflavin, vitamin B6, and magnesium.
A prescription form of vitamin B12 can be given by injection or as a nasal gel.
Vitamin B12 is also available in a form that dissolves under the tongue (sublingual).
The Recommended Dietary Allowance (RDA) for vitamins reflects how much of each vitamin most people should receive on a daily basis. The RDA for vitamins may be used as goals for each person.
How much of each vitamin you need depends on your age and gender. Other factors, such as pregnancy and illnesses, are also important. Women who are pregnant or breast-feeding need higher amounts. Ask your health care provider which amount is best for you.
Dietary Reference Intakes for vitamin B12:
Infants (adequate intake)
0 - 6 months: 0.4 micrograms per day (mcg/day)
7 - 12 months: 0.5 mcg/day
1 - 3 years: 0.9 mcg/day
4 - 8 years: 1.2 mcg/day
9 - 13 years: 1.8 mcg/day
Adolescents and Adults
Males and females age 14 and older: 2.4 mcg/day
Pregnant teens and women: 2.6 mcg/day
Breastfeeding teens and women: 2.8 mcg/day
Escott-Stump S, ed. Nutrition and Diagnosis-Related Care. 6th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2008.
Sarubin Fragaakis A, Thomson C. The Health Professional's Guide to Popular Dietary Supplements. 3rd ed. Chicago, Il: American Dietetic Association; 2007.
Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. Washington, DC: National Academy Press; 1998.
Alison Evert, MS, RD, CDE, Nutritionist, University of Washington Medical Center Diabetes Care Center, Seattle, Washington. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.