Iron and zinc interactions among pregnant Nepali women

Abstract

Few studies have examined the biologic impact of iron and zinc when given at a ratio of 2:1 during pregnancy. We examined the change in serum zinc after 3 weeks among night blind Nepali pregnant women who were randomly assigned to receive zinc (25 mg) or placebo, stratified by whether they received iron (60 mg) - folate (400 μg) or not. Further, we looked at change in hemoglobin (Hb) and serum ferritin concentrations by whether women had received iron or not, stratified by supplementation group (zinc or placebo). Women who received iron were anemic (Hb < 110 g/L) at baseline. The treatment groups were comparable on serum zinc and ferritin and Hb concentration at baseline. There was a mean increase of ∼1.6 μmol/L ( p < 0.05) in the serum zinc concentration in women receiving zinc relative to a decline of ∼0.5 μmol/L in the placebo group, which was similar both in women who received iron or not. Similarly, treatment with iron resulted in significant increases in Hb of 4.8 g/L and 7.8 g/L, and in serum ferritin of 12.2 μg/L and 13.6 μg/L among those in the zinc and placebo groups, respectively. However, there was some evidence that zinc supplementation may adversely effect iron status among women with initial Hb of <85 g/L. This analysis shows an overall lack of a negative iron-zinc interaction when given at a ratio of 2:1.