Objective: Many children are at high risk of both goiter and iron deficiency in Iran. Because iron deficiency may impair the efficacy of iodine supplementation, the aim of this study was to determine the relation between serum ferritin and goiter, urinary iodine, and thyroid hormones following iodized salt supplementation.
Design: A cross-sectional study of schoolchildren in 26 Iranian provinces.
Methods: In a national iodine deficiency disorders (IDD) monitoring program, 36,178 schoolchildren, approximately 1200 from each province, received goiter grading by WHO criteria. Urine and serum samples were collected from 2917 children and assayed for urinary iodine and serum ferritin, T4, T3, and thyroid-stimulating hormone (TSH) concentrations.
Results: Total goiter rates were 80 and 20% in children with ferritin concentrations < 10 mg/dL and > or = 10 mg/dL, respectively (p < 0.001). Increased serum T3 and decreased resin T3 uptake was present in those with lower serum ferritin levels; however, free T3 and T4 index, serum T4, and TSH were not significantly different between those with low and normal ferritin.
Conclusion: Iron deficiency is associated with a high prevalence of goiter in Iranian schoolchildren.