Urinary Iodine Status and Associated Factors among Children Aged 3–5 Years and the Elderly in Thailand, 2023–2025
DOI:
https://doi.org/10.59096/osir.v19i2.280462Keywords:
iodine deficiency, urinary iodine concentration, universal salt iodization, older adults, preschool children, ThailandAbstract
Objectives: To assess the iodine status and identify associated dietary factors among children aged 3–5 years and adults aged ≥60 years in Thailand within the context of current national fortification policies.
Methods: A national cross-sectional survey from 2023 to 2025 was conducted using multi-stage cluster sampling across 77 provinces. Spot urinary iodine concentrations (UIC) were measured in 11,028 children and 11,183 older adults. Dietary behaviors were assessed via questionnaires and analyzed using multivariable linear regression to identify independent predictors of UIC while adjusting for socioeconomic and demographic confounders.
Results: The national median UIC level for children aged 3–5 years was 222.0 ug/L (interquartile range (IQR) 204.4–238.9) and for older adults was 111.4 ug/L (IQR 96.2–136.0). Among children, processed food consumption was associated with higher UIC (adjusted regression coefficients (adjusted β) 17.55, 95% confidence interval (CI) 0.68 to 34.43). In older adults, a positive trend was observed between the consumption of iodine-fortified condiments and iodine status (adjusted β 10.66, 95% CI −0.24 to 21.56). Lower UIC was independently associated with advanced age (≥81 years: adjusted β −18.76, 95% CI −33.12 to −4.39), and history of kidney disease (adjusted β −27.30, 95% CI −50.76 to −3.83) and diabetes mellitus (adjusted β −10.72, 95% CI −19.94 to −1.50).
Public Health Recommendations: Adequate population-level iodine status for both groups (according to UNICEF/ICCIDD and WHO criteria), underscores the importance of universal salt iodization programs and iodine fortification policies for condiments in Thailand. Addressing regional and clinical vulnerabilities requires strict enforcement of fortification standards to ensure the consistent delivery of sufficient iodine to the population. Policies promoting dietary patterns aligned with national guidelines should also be strengthened to safeguard population-wide iodine security.
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