EFFECTIVE TREATMENT OF COBALAMIN DEFICIENCY WITH ORAL COBALAMIN

Because cobalamin deficiency is routinely treated with parenteral coba lamin, we investigated the efficacy of oral therapy. We randomly assig ned 38 newly diagnosed cobalamin deficient patients to receive cyanoco balamin as either 1 mg intramuscularly on days 1, 3, 7, 10, 14, 21, 30 , 60, and 90 or 2 mg orally on a daily basis for 120 days. Therapeutic effectiveness was evaluated by measuring hematologic and neurologic i mprovement and changes in serum levels of cobalamin (normal, 200 to 90 0 pg/mL) methylmalonic acid (normal, 73 to 271 nmol/L), and homocystei ne (normal, 5.1 to 13.9 mu mol/L). Five patients were subsequently fou nd to have folate deficiency, which left 18 evaluable patients in the oral group and 15 in the parenteral group. Correction of hematologic a nd neurologic abnormalities was prompt and indistinguishable between t he 2 groups. The mean pretreatment values for serum cobalamin, methylm alonic acid, and homocysteine were, respectively, 93 pg/mL, 3,850 nmol /L, and 37.2 mu mol/L in the oral group and 95 pg/mL, 3,630 nmol/L, an d 40.0 mu mol/L in the parenteral therapy group. After 4 months of the rapy, the respective mean values were 1,005 pg/mL, 169 nmol/L, and 10. 6 mu mol/L in the oral group and 325 pg/mL, 265 nmol/L, and 12.2 mu mo l/L in the parenteral group. The higher serum cobalamin and lower seru m methylmalonic acid levels at 4 months posttreatment in the oral grou p versus the parenteral group were significant, with P < .0005 and P < .05, respectively. In cobalamin deficiency, 2 mg of cyanocobalamin ad ministered orally on a daily basis was as effective as 1 mg administer ed intramuscularly on a monthly basis and may be superior. (C) 1998 by The American Society of Hematology.