Zinc supplementation during pregnancy: effects on selected blood constituents and on progress and outcome of pregnancy in low-income women of Mexican descent

Abstract

The effects of zinc supplementation on levels of various blood constituents and the outcome of pregnancy in 213 Hispanic women attending a prenatal clinic in Los Angeles was assessed in this double-blind study. The women were randomized into either a control (C) or a zinc-supplemented (Z) group and received similar vitamin and mineral supplements except that 20 mg zinc was added to the Z group's capsules. At the final interview, women (C + Z) with low serum Zn levels (≼ 53 µg/dl) had higher (p < 0.01) mean ribonuclease activity and lower (p < 0.01) mean δ-aminolevulinic acid dehydratase activity than women with acceptable serum zinc levels. The incidence of pregnancy-induced hypertension was higher (p < 0.003) in the C than in the Z group, but pregnancy-induced hypertension was not associated with low serum zinc levels at either the initial or final interview. The expected increase in serum copper levels was greater (p < 0.001) in women with pregnancy-induced hypertension (C + Z) than in normotensives. Except for pregnancy-induced hypertension, there was a higher incidence of abnormal outcomes of pregnancy in the noncompliers than in the compilers (C + Z).