Iodine Deficiency and Excess in Children and Related Factors in Alborz Province: A Cross-Sectional Study Publisher



Baladastian S ; Bahreini F ; Nouri A ; Morvaridi M ; Tavakoli H
Source: BMC Nutrition Published:2026

Abstract

Background: Both insufficient and excessive iodine intake can result in adverse health effects, especially in children. Despite the implementation of universal salt iodization (USI) in Iran, regional variations may persist. This study aimed to assess urinary iodine concentration (UIC) and associated factors among primary school students in Alborz Province. Methods: In this cross-sectional study, 228 students aged 7–11 years (118 girls and 110 boys) were selected from 48 urban and rural schools in Alborz Province through multistage cluster sampling. Spot urine samples were collected to measure UIC using the modified Sandell-Kolthoff method. The iodine content of household salt was also analyzed. A 24-hour dietary recall assessed recent food intake, and structured questionnaires evaluated household iodized salt use and storage practices. Results: Out of 228 children (mean age: 8.81 ± 0.07 years; 52% girls), the median UIC was 190.0 µg/L (IQR: 130.0–280.0). A total of 19.6% of participants had UIC < 100 µg/L, while 14.0% had UIC ≥ 300 µg/L. The mean iodine content of household salt was 35.86 ± 1.06 ppm; 12.4% of samples had iodine levels below 20 ppm, and 46.7% exceeded 40 ppm. Children in households using salt with < 20 ppm iodine had significantly higher odds of UIC < 100 µg/L (AOR: 3.42; 95% CI: 1.42–8.22; p = 0.006). In contrast, adding salt at the end of cooking was associated with lower odds of iodine deficiency (AOR: 0.41; 95% CI: 0.20–0.85; p = 0.017). No notable associations were observed for sociodemographic or dietary variables. Conclusions: Both iodine deficiency and excess were observed among school-aged children in Alborz. Iodine status was linked to household salt iodine content and the timing of salt addition during cooking, while no significant associations were found with sociodemographic or dietary factors. © The Author(s) 2026.