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Safety
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Allergies
Vitamin B12 supplements should be avoided in people sensitive or allergic to cobalamin, cobalt, or any other product ingredients.
Side Effects and Warnings
Caution should be used in patients undergoing angioplasty since an intravenous loading dose of folic acid, vitamin B6, and vitamin B12 followed by oral administration taken daily after coronary stenting might actually increase restenosis rates. Due to the potential for harm, this combination of vitamins should not be recommended for patients receiving coronary stents.
Itching, rash, transitory exanthema, and urticaria have been reported. Vitamin B12 and pyridoxine has been associated with cases of rosacea fulminans, characterized by intense erythema with nodules, papules, and pustules. Symptoms may persist for up to four months after the supplement is stopped, and may require treatment with systemic corticosteroids and topical therapy.
Diarrhea has been reported.
Peripheral vascular thrombosis has been reported. Treatment of vitamin B12 deficiency can unmask polycythemia vera, which is characterized by an increase in blood volume and the number of red blood cells. The correction of megaloblastic anemia with vitamin B12 can result in fatal hypokalemia and gout in susceptible individuals, and it can obscure folate deficiency in megaloblastic anemia. Caution is warranted.
Vitamin B12 is contraindicated in early Leber's disease, which is hereditary optic nerve atrophy. Vitamin B12 can cause severe and swift optic atrophy.
Pregnancy and Breastfeeding
Vitamin B12 is likely safe when used orally in amounts that do not exceed the recommended dietary allowance (RDA).
There is insufficient reliable information available about the safety of larger amounts of vitamin B12 during pregnancy.
NS_patient-vitaminb12
Portions of this document last updated:Sept. 1, 2009
THE NATURAL STANDARD RESEARCH COLLABORATION
(www.naturalstandard.com)
