Precautions
Folic Acid alone is improper therapy in the treatment of pernicious anemia and other megaloblastic anemias where vitamin B12 is deficient. Daily doses of 0.1 mg or more of folic acid (vitamin B9) may obscure pernicious anemia. Hematologic improvement can occur while neurological damage progresses. Exclusive use of folic acid to treat vitamin B12-deficient macrocytic anemia can lead to progressive and irreversible neurological damage. Vitamin B12 deficiency allowed to progress for over 3 months may cause permanent spinal cord lesions. Doses of vitamin B12 exceeding 10 mcg daily may produce hematologic response in patients with vitamin B9 deficiency. Indiscriminate administration may mask the true diagnosis.