Studies on the Minimum Daily Requirement for Vitamin B12 — Hematopoietic Responses to 0.1 Microgm. of Cyanocobalamin or Coenzyme B12, and Comparison of Their Relative Potency | NEJM
Vitamin B12 and the Vegan Diet - Today's Dietitian Magazine
Vitamin B12 | Linus Pauling Institute | Oregon State University