Because it may mask the hematologic abnormalities while neurological damage progresses, folic acid should not be used in the therapy of patients with vitamin B12 deficiency of any cause, unless there is associated folate deficiency. Megaloblastic anemia secondary to vitamin B12 deficiency; folic acid may obscure pernicious anemia and may produce hematologic remission while neurological damage progresses. The folic acid content of one tablet a day however, is unlikely to mask pernicious anemia should this condition be present. For iron utilization disturbances, excess iron storage may occur.