Efficacy of Multiple Micronutrient Supplements during Pregnancy on Zinc Status among Pregnant Women in Ghana: A Randomized Trial.

BACKGROUND

Multiple micronutrient deficiencies, including zinc deficiency, remain highly prevalent among pregnant women in many low- and middle-income countries and are associated with a multitude of adverse outcomes.

OBJECTIVES

The objectives of this analysis were to assess the impacts of prenatal multiple micronutrient supplements (MMS) compared with iron and folic acid (IFA) supplements on maternal zinc status among pregnant women at 36 weeks of gestation and to assess associations with birth outcomes.

METHODS

We analyzed plasma zinc concentrations at baseline (<20 weeks of gestation) and late pregnancy (36 weeks of gestation) from a subset of pregnant women randomly assigned to receive either daily MMS (containing 30 mg/d zinc) or IFA supplements (n = 125/group) in the International Lipid-Based Nutrient Supplements (iLiNS)-DYAD trial in Ghana. Gestational and infant anthropometric outcomes were measured at birth.

RESULTS

At baseline, mean ± standard deviation (SD) plasma zinc concentration was 61.9 ± 13.6 μg/dL, and 16.5% of women were zinc deficient. At 36 weeks of gestation, mean ± SD plasma zinc concentration was lower compared with baseline, but did not differ significantly between groups (IFA: 52.2 ± 8.1 μg/dL compared with MMS: 52.9 ± 9.5 μg/dL; P = 0.25). Similarly, there was no difference in the estimated prevalence of zinc deficiency between groups at 36 wk (IFA: 43.0% compared with MMS: 38.4%; P = 0.24). There were few significant associations between maternal plasma zinc concentrations or zinc deficiency and birth outcomes.

CONCLUSIONS

Daily MMS supplementation for ≥16 wk during pregnancy did not significantly increase plasma zinc concentrations, and the prevalence of zinc deficiency increased over the course of pregnancy. Other complementary interventions to address both nutritional and underlying nonnutritional causes of zinc deficiency may be necessary to improve zinc status during pregnancy in this and other vulnerable populations. The trial was registered at clinicaltrials.gov as NCT00970866. https://clinicaltrials.gov/study/NCT00970866.