1. Folic acid in daily doses of 15 to 50 mg., orally, or 20 mg. intramuscularly, usually produced a submaximal reticulocytosis in patients with pernicious anemia.
2. In 3 patients the hemoglobin and red cells rose to a level of about 12.0 Gm. and 4.3 million respectively without further rise after 3 months of therapy.
3. Folic acid in the above doses failed to prevent the development or progression of neurological symptoms indicative of subacute combined sclerosis.
4. In 5 patients folic acid in doses of 5 or 10 mg. orally daily combined with ½ unit of liver extract injected intramuscularly daily produced a reticulocytosis greater than that anticipated from adequate liver extract therapy alone.
5. With combined liver extract and folic acid therapy there was evidence of improvement in the symptoms and signs of subacute combined sclerosis in 3 patients.
6. Folic acid, combined with ½ unit of liver extract, was found to produce a complete hematological remission.
7. Folic acid, alone or in combination with small doses of liver extract, produced an improvement in appetite and general well-being in patients with pernicious anemia.
8. The possible enhancing effect of liver extract when combined with folic acid cannot be due to the folic acid content of the former since 1 unit of liver extract contains only 0.38 micrograms of folic acid.31
9. Folic acid administered to a patient with macrocytic anemia due to faulty postoperative intestinal digestion and absorption, produced a complete remission in the blood picture and a marked improvement in signs and symptoms.