Levels of serum ferritin, folate, and vitamin B12 in pregnant women at term who had been supplemented with iron and folate.

The levels of serum ferritin, folates, and vitamin B12 in relation to the hematologic values were measured in 66 pregnant women at term who had been supplemented with iron (100 mg/day) and folate (350 microgram/day). The levels of hemoglobin in pregnant women were similar to the controls;' however, levels of ferritin and transferrin saturation were decreased and showed a correlation with the hemoglobin. The MCV increased, whereas folate and vitamin B12 decreased, but no correlation was found between these values. These results suggest that in pregnant women (a) serum ferritin and transferrin saturation reflect the iron available for erythropoiesis, (b) the iron supplementation of 100 mg/day in the population studied is not sufficient, and (c) the macrocytosis is independent of the folate and vitamin B12 levels.