Cyanocobalamin is the principal form of vitamin B12 for commercial use in fortified foods and dietary supplements. Once absorbed through the intestine, cyanocobalamin is converted to the active forms of vitamin B12 in the body. No adverse effects have been associated with B12 intake from food or supplements in healthy individuals at amounts far exceeding the recommended daily value 1.


  1. Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, D.C.: National Academy Press, 2000.