Diet quality and its relationship with iodine status in pregnant women living in a Brazilian region where table salt is iodine-fortified according to Public Health Policies

Abstract

Background Conditions related to iodine status (IS) in pregnancy should be addressed to help public health strategies. In the present study, we evaluated diet quality (DQ) and its relationship with IS in pregnant women from a coastal Brazilian state where table salt is iodine fortified. Methods In a cross-sectional study, 199 women were evaluated on three different days of their first trimester of pregnancy. In every visit, a urinary spot sample was requested to assess urinary iodine concentration (UIC); and a 24-hour dietary recall related to the time that they collected the urine was also applied by a nutritionist. Total and component scores were estimated for the Healthy Eating Index-2015 (HEI-2015). The association between DQ and IS was evaluated, considering adequate UIC as the reference group (RG). Results The median total score for HEI-2015 was 45.8 points, being higher in the insufficient UIC than in RG (48.1 vs. 41.3 in the RG; p = 0.04). Insufficiency of iodine was related to higher scores in “whole fruit” (B = 0.712 [CI: +0.421/+1.002]), “total fruit” (B = 0.744[-0.002/+0.006]), “total vegetables” (B = 0.678([+ 0.444/+0.913]) and “refined grains” (B = 0.685 [+ 0.406/+0.964]). On opposite, excessive IS was related to lower scores in the same components. Conclusions pregnant women with insufficient IS had better diet quality, with higher consumption of fruits and vegetables, as also lower intake of refined grains. In contrast, poor DQ was associated with excessive UIC during pregnancy. The necessity of iodine supplementation for pregnant women should be better explored even in a region adopting iodine fortified table salt as public health policy.