Cyanocobalamin Therapy Effect in Folic Acid Deficiency

Abstract

Introduction It is currently well established that supraphysiologic doses of folic acid may reverse the hematologic abnormality in patients who are deficient in vitamin B₁₂.^1-4On the other hand, the effect of large doses of cyanocobalamin in folic acid-deficient patients has not been clearly determined. Although responses to cyanocobalamin therapy have occasionally been observed in megaloblastic anemia associated with infancy,^5A,^5Bpregnancy^6Aand the puerperium,^6A,6Bcirrhosis of the liver,^7,8intestinal malabsorption,⁹and the ingestion of anticonvulsant drugs,¹⁰they have often been suboptimal or inadequate, whereas folic acid therapy induces prompt remission. Interpretation of these results have been complicated by a number of factors, including: (1) lack of reliable laboratory measures of deficiency of vitamin B₁₂and folic acid, (2) difficulty in control of dietary folic acid intake, especially in the light of recent evidence indicating the therapeutic efficacy of 25μg. and 50μg.