What is the recommended dietary allowance (RDA) of vitamin B12?

The recommended dietary allowance (RDA) of vitamin B12 varies depending upon your age. For children, the RDA for vitamin B12 is 0.9 micrograms (mcg) for ages 1 to 3, 1.2 mcg for ages 4 to 8, and 1.8 mcg for ages 9 to 13. The RDA for people ages 14 and older is 2.4 mcg, with slightly higher levels recommended for pregnant or breast-feeding women.

You can meet your RDA by eating foods that contain vitamin B12, including canned and fresh fish, beef, eggs and dairy products, or by taking supplements if your doctor recommends them for you.
Dr. David L. Katz, MD, MPH
Preventive Medicine
Preventive Medicine Specialist Dr. David Katz discusses the recommended dietary allowance (RDA) of vitamin B12. Watch Dr. Katz's video for information on preventive medicine and overall wellness.
Michael T. Murray, ND
Naturopathic Medicine

Vitamin B12 (cobalamin) is necessary in only very small quantities. The RDA is 2.0 micrograms. Vitamin B12 is found in significant quantities only in animal foods. The richest sources are liver and kidney, followed by fish, eggs, meat, and cheese. Strict vegetarians (vegans) are often told that fermented foods, such as tempeh are excellent sources of vitamin B12, and, depending upon the medium on which it is grown, nutritional brewer's yeast may also provide B12. However, in addition to the tremendous variation in B12 content in fermented foods and brewer's yeast, there is some evidence that the form of B12 in these foods is not exactly the form that meets our bodily requirements. Although the vitamin B12 content of certain cooked sea vegetables is in the same range as beef, it is not known if this form is utilized in the same manner either. Therefore, at this time it appears to be an extremely good idea for vegetarians to supplement their diets with vitamin B12.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.