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Vitamin B12

How does Vitamin B12 work?

Vitamin B12 is required for the proper function and development of the brain, nerves, blood cells, and many other parts of the body.

Are there safety concerns?

Vitamin B12 is LIKELY SAFE for most people when taken by mouth, applied to the skin, taken through the nose, or administered as a shot..

Mild itching has been reported in one person who used a specific avocado oil plus vitamin B12 cream for psoriasis.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Vitamin B12 is LIKELY SAFE for pregnant or breast-feeding women when taken by mouth in the amounts recommended. The recommended amount for pregnant women is 2.6 mcg per day. Breast-feeding women should take no more than 2.8 mcg per day. Don't take larger amounts. The safety of larger amounts is unknown.

High numbers of red blood cells (polycythemia vera): The treatment of vitamin B12 deficiency can unmask the symptoms of polycythemia vera.

Abnormal red blood cells (megaloblastic anemia): Megaloblastic anemia is sometimes corrected by treatment with vitamin B12. However, this can have very serious side effects. Don't attempt vitamin B12 therapy without close supervision by your healthcare provider.

Leber's disease, a hereditary eye disease: Do not take vitamin B12 if you have this disease. It can seriously harm the optic nerve, which might lead to blindness.

Allergy or sensitivity to cobalt or cobalamin: Do not use vitamin B12 if you have this condition.

Post-surgical stent placement: Avoid using a combination of vitamin B12, folate, and vitamin B6 after receiving a coronary stent. This combination may increase the risk of blood vessel narrowing.

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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