SAT-403 Iodine Status And Salt Iodization In Pregnant Women: Discrepancy Between Legislative Adequacy And Biological Sufficiency

Abstract Disclosure: L.A. Gross: None. K.C. Oliveira: None. R.E. Silva: None. N. Tenenbaum: None. M.Y. Melo: None. G. Papa: None. B.F. Aime: None. K.R. Gandolphi: None. G. Giannocco: None. D. Macellaro: None. R.M. Biscolla: None. C.P. Camacho: None. M.I. Chiamolera: None. Background: Iodine is essential for thyroid hormone production, particularly during pregnancy, when maternal and fetal health are highly dependent on sufficient iodine intake. This study aimed to assess iodine status among pregnant women in São Paulo, Brazil, through urinary iodine concentration (UIC), a lifestyle and dietary questionnaire, and measurement of iodine content in household cooking salt. Methods: Fifty-nine pregnant women attending a specialized thyroid disorders in pregnancy clinic were enrolled. UIC was measured using a colorimetric assay, and participants completed a detailed questionnaire addressing dietary habits, iodine supplementation, and sociodemographic variables. Salt samples brought from home were analyzed for iodine content. In Brazil, salt iodization has been mandatory since 1953, and the current regulation (Anvisa RDC n° 23/2013) requires iodine concentrations between 15 and 45 mg/kg in salt for human consumption. Results: UIC analysis revealed substantial variability: 35.6% of women were iodine deficient (UIC ≤149 μg/L), 27.1% had adequate levels (UIC 150-299 μg/L), and 37.3% had excess (UIC ≥300 μg/L). A statistically significant association was found between UIC and family income (p<0.05). No significant associations were found between UIC and reported dietary habits or iodine supplementation. The iodine content of salt samples ranged from 24 to 42 μg/g, with a mean of 26 μg/g. All samples complied with national legislation. Discussion: Despite regulatory adequacy of salt iodine content, over one-third of pregnant women were iodine deficient. This mismatch suggests that iodized salt alone may not guarantee sufficient iodine intake during pregnancy, potentially due to variability in individual dietary practices, bioavailability, or iodine metabolism. The association with family income points to underlying socioeconomic determinants of nutritional adequacy. Conclusion: Iodine deficiency and excess coexist in this pregnant population, even under a long-standing universal salt iodization policy. These findings underscore the need for individualized assessments and nutritional surveillance during pregnancy. Importantly, the results provide evidence to support the refinement of public health strategies and inform iodine-related policy-making, aiming to ensure that regulatory measures translate into effective biological sufficiency for all pregnant women. Presentation: Saturday, July 12, 2025