Consumption of multiple micronutrients or small-quantity lipid-based nutrient supplements containing iodine at the recommended dose during pregnancy, compared with iron and folic acid, does not affect women’s urinary iodine concentration in rural Malawi: a secondary outcome analysis of the iLiNS DYAD trial

Objectives: Inadequate iodine intake during pregnancy increases the risk of neo natal morbidity and mortality. We aimed to evaluate whether prenatal supplements containing iodine affect urinary iodine concentrations (UIC) of pregnant women in Malawi. Design: A randomised controlled trial. Pregnant women (n 1391) were assigned to consume 60 mg/d Fe and 400 μg/d folic acid (IFA) or 18 vitamins and minerals including 250 μg/d iodine (MMN) or 20 g/d small-quantity lipid-based nutrient sup plements (SQ-LNS) with similar nutrient contents as MMN group, plus macronu trients (LNS) until childbirth. In a sub-study (n 317), we evaluated group geometric mean urinary iodine concentration (UIC) (μg/L) at 36 weeks of gestation controlling for baseline UIC and compared median (baseline) and geometric mean (36 weeks) UIC with WHO cut-offs: UIC < 150, 150–249, 250–499 and ≥500 reflect ing insufficient, adequate, above requirements and excessive iodine intakes, respectively. Setting: Mangochi District, Malawi. Participants: Women ≤20 weeks pregnant. Results: Groups had comparable background characteristics. At baseline, overall median (Q1, Q3) UIC (319 (167, 559)) suggested iodine intakes above require ments. At 36 weeks, the geometric mean (95 % CI) UIC of the IFA (197 (171, 226)), MMN (212 (185, 243)) and LNS (220 (192, 253)) groups did not differ (P = 0·53) and reflected adequate intakes. Conclusions: In this setting, provision of supplements containing iodine at the rec ommended dose to pregnant women with relatively high iodine intakes at base line, presumably from iodised salt, has no impact on the women’s UIC. Regular monitoring of the iodine status of pregnant women in such settings is advisable. Clinicaltrials.gov identifier: NCT01239693.

Description

Research Article

Keywords

iLiNS DYAD-Malawi, small-quantity lipid-based nutrient, supplements, Multiple micronutrients, Pregnant women, Iodine intakes, Urinary iodine concentration