The effect of vitamin B12 on the anemia and combined system disease of addisonian pernicious anemia.

The effect of the parenteral administration of vitamin B(12) has been observed in eight patients with Addisonian pernicious anemia. Vitamin B(12) in initial doses of 50 micrograms or 25 micrograms induced satisfactory reticulocyte response and a return of erythrocyte count to within normal range in 60 days. In only two of the patients were secondary reticulocyte responses induced on a second injection of vitamin B(12). Concurrently with the hemopoietic response, the bone marrow changed from megaloblastic hyperplasia to normoblastic distribution. The paresthesias associated with combined system disease as well as disturbances in position sense and locomotor function may be entirely relieved or greatly diminished following injections of vitamin B(12). Maintenance injections of vitamin B(12) may be from 30 to 50 micrograms at intervals of one month, the amount depending upon the individual case. Vitamin B(12) may be used without untoward symptoms in patients previously sensitive to liver extract.