The apparent effect of iron supplementation on serum selenium levels in teenage pregnancy

Numerous studies have suggested a significant role of selenium in the preve ntion of gynecological carcinoma. These were epidemiological and prospectiv e in humans and therapeutic in laboratory animals. However, no studies have been reported regarding the normal serum selenium levels during pregnancy. The maternal total blood volume increases 30-50% during the second and thi rd trimesters, resulting in lower measured serum levels for those metabolit es, which are not increased significantly during pregnancy. A longitudinal study of the serum selenium levels in teenage pregnancy during the last two trimesters and 3 mo postpartum showed progressive elevation from 49 +/- 7 mug/dL after the 32nd week of pregnancy to 114 +/- 7 mug/dL at term, which was statistically significant (p less than or equal to 0.001). Prenatal sup plementation with 18 mg of iron per day prevented this elevation. The resul ts of this study suggest that serum selenium levels in women normally doubl e during pregnancy and this doubling is prevented by the minimal daily supp lementation of 18 mg of iron, which may be due to increased absorption of s elenium into the erythrocytes and incorporation into the glutathione peroxi dase enzyme.