Use of iodized salt in the households improves the iodine status of pregnant women and school-age children in Donetsk, Ukraine: A double-blind randomized controlled trial

Abstract

This study analyzed the effect of iodized salt consumption on the iodine status of pregnant women and school children living in the households of Donetsk, Ukraine. 160 households with a healthy pregnant woman and a child aged 6–12 years were assigned in concealed sequence 1 : 1 to the use of either common or iodized salt. Casual urine samples were collected and the consumption of specific foods was obtained verbally from the women and the children during a baseline and a follow-up visit in each household. All the women (age 30 years; pregnancy duration 20 weeks) and the children (age 8.5 years) completed the trial without any adverse event. At the baseline visit, the mean household salt iodine content was 10.2 mg/kg (SD 3.1) and the median urinary iodine (UI) concentration in the women (89 μg/L) and the children (101 μg/L) was not significantly different. The salt iodine content during the trial in the experimental households was 43.3 mg/kg (SD 4.6) and starkly higher (p<0.001) than in comparison house- holds (11.4 mg/kg; SD 5.1). The final UI of the pregnant women (141μg/L; 95% CI: 123–163) in experimental households was lower (p < 0.05) than of the children (169μg/L; 95% CI: 147–194), but the net effect of iodized salt consumption on the UI levels of the women (73μg/L; 95% CI: 66–81) was significantly higher (p<0.01) than that of the children (59μg/L; 95% CI: 53–67). The baseline UI (in both groups), and the consumption of marine fish (both groups) and of dairy products other than cheese (in children) were significant effect modifiers. Introduction of iodized salt in the households of Donetsk was associated with adequate iodine intake in school-age children but it did not realize sufficient iodine intake in pregnant women, despite the greater net effect on the UI concentration in the latter group.