In this Article
- What other names is Vitamin B12 known by?
- What is Vitamin B12?
- How does Vitamin B12 work?
- Are there safety concerns?
- Are there any interactions with medications?
- Dosing considerations for Vitamin B12.
Interaction Rating: Major Do not take this combination.
Vitamin B12 is important for producing new blood cells. Chloramphenicol might decrease new blood cells. Taking chloramphenicol for a long time might decrease the effects of vitamin B12 on new blood cells. But most people only take chloramphenicol for a short time, so this interaction isn't a big problem.
The typical general supplemental dose of vitamin B12 is 1-25 mcg per day.
The recommended dietary allowances (RDAs) of vitamin B12 are: Infants 0-6 months, 0.4 mcg; infants 7-12 months, 0.5 mcg; children 1-3 years, 0.9 mcg; children 4-8 years, 1.2 mcg; children 9-13 years, 1.8 mcg; older children and adults, 2.4 mcg; pregnant women, 2.6 mcg; and breast-feeding women, 2.8 mcg. Because 10% to 30% of older people do not absorb food-bound vitamin B12 efficiently, those over 50 years should meet the RDA by eating foods fortified with B12 or by taking a vitamin B12 supplement. Supplementation of 25-100 mcg per day has been used to maintain vitamin B12 levels in older people.
- For vitamin B12 deficiency or pernicious anemia: cyanocobalamin doses of 300-10,000 mcg (microgram) daily have been used. However, some evidence suggests that the most effective oral dose is between 647-1032 mcg/day.
- For high blood levels of homocysteine: vitamin B12 500 mcg in combination with 0.5-5 mg folic acid and 16.5 mg pyridoxine has been used.
- For preventing age-related macular degeneration (AMD): vitamin B12 1 mg, folic acid 2.5 mg, and pyridoxine 50 mg daily has been studied.
- For atopic dermatitis (eczema): a specific vitamin B12 0.07% cream (Regividerm) applied twice daily has been used.
- For psoriasis: a specific cream (Regividerm, Regeneratio Pharma AG, Wuppertal, Germany) containing avocado oil plus vitamin B12 0.7 mg/gram applied for 12 weeks twice daily has been used.
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.
Get the latest treatment options.