Supplementation during pregnancy with small‐quantity lipid‐based nutrient supplements or multiple micronutrients, compared with iron and folic acid, increases women's urinary iodine concentration in semiurban Ghana: A randomized controlled trial

There is little information on whether prenatal multiple micronutrient (MMN) supplements containing iodine affect women's iodine status. In the International Lipid‐based Nutrient Supplements DYAD‐Ghana trial, we aimed to assess women's urinary iodine concentration (UIC, μg/L) during pregnancy, as one of the planned secondary outcomes. Women ( n  = 1,320) <20 weeks of gestation were randomized to consume 60 mg iron and 400 μg folic acid per day (iron and folic acid [IFA]); 18 vitamins and minerals including 250 μg iodine per day (MMN); or 20 g/day of small‐quantity lipid‐based nutrient supplements (LNS) with the same and additional 4 vitamins and minerals as the MMN (LNS). In a subsample ( n  = 295), we tested differences in groups' geometric mean UICs at 36 weeks of gestation controlling for baseline UIC and compared the geometric means (approximately median UICs) with the World Health Organization (WHO) cut‐offs: median UIC <150, 150–249, and ≥500 reflecting low, adequate, and excessive iodine intakes, respectively. At baseline, overall median UIC was 137. At 36 weeks of gestation, controlling for baseline UIC, geometric mean (95% confidence interval) UICs of the MMN (161 [133, 184]) and LNS (158 [132, 185]) groups did not differ; both values were significantly greater (overall p  = .004) than that of the IFA group (116 [101, 135]). The median UICs of the MMN and LNS groups were within the WHO “adequate” range, whereas that of the IFA group was below the WHO adequate range. In this setting, supplementation during pregnancy with small‐quantity LNS or MMN providing iodine at the WHO‐recommended dose, compared with IFA, increases the likelihood of adequate iodine status.