Erythrocyte and plasma folate levels were studied before treatment in 20 patients with iron deficiency anemia and in 23 patients with megaloblastic anemia due to folate deficiency. Fourteen of the cases of iron deficiency anemia were also studied after treatment with oral iron alone. Fifty-seven normal persons were used as controls.
The mean erythrocyte folate (ng./ml. packed cells) was significantly increased in iron deficiency anemia and significantly depressed in folate deficiency anemia. After treatment with oral iron alone, the mean erythrocyte folate level fell to normal in the iron deficiency anemia group. The mean corpuscular folate (ng. x 108-8) was also significantly raised in iron deficiency: in eight of 10 cases this fell after treatment, but the overall fall was not significant. The plasma folate rose in iron deficiency anemia after oral iron treatment.