Treatment of Pernicious Anemia with Orally Administered Cyanocobalamin (Vitamin B12)

Introduction Parenteral injection of cyanocobalamin (Vitamin B₁₂) is well established as an effective and reliable treatment for pernicious anemia. In contrast, currently available preparations for oral use have proved to be much less dependable.¹A study was initiated in 1950 in the hematology clinic of The Johns Hopkins Hospital to determine whether relatively large amounts of pure cyanocobalamin, when administered orally without intrinsic factor or other adjuvants, would provide adequate therapy for patients with pernicious anemia. The early results of this investigation²⁻⁴as well as those obtained in other clinics⁵⁻¹¹were favorable. This paper provides further observations on a group of patients receiving various doses of orally administered cyanocobalamin for periods of up to six and one-half years. Materials and Methods The diagnosis of pernicious anemia had been well established by clinical and hematological criteria in each patient chosen to participate in this study. In many