Vitamin B12 Recommendations

Step 1

If you have a regular source of B12, skip to Step 2. If you have not had a regular source of B12 for some time, buy a bottle of 1,000 µg (or greater) of cyanocobalamin B12 tablets.

Chew 2,000 µg once a day, for 2 weeks. You can break the remaining tablets in half or quarters for Step #2. It's okay to take more than recommended. Then follow the advice under Step #2.

In rare case, someone might have an acne-like response to such large doses of vitamin B12. If that happens to you, skip to Step 2 and opt for one of the lower dose regimens.

Step 2


Click here for an explanation of how these recommendations were formulated.


1. Lower limit based on minimum recommendations in What Every Vegan Should Know about Vitamin B12.

2. In a single dose, B12 absorption drops to 1-1.5% for the amounts above 5 µg.

3. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 2000.

4. Sharabi A, Cohen E, Sulkes J, Garty M. Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. Br J Clin Pharmacol. 2003 Dec;56(6):635-8. | link