Background and objective: Iodine deficiency in early years of life can cause important disorders in body growth and development. The aim of this study was to determine the prevalence of iodine deficiency in 4 year-old schoolchildren from the town of Mataró (Barcelona, Spain) and to know the factors associated with this nutritional deficiency.
Patients and method: A population-based cross-sectional study was designed, which included all 4 year-old schoolchildren of this town. A physicians team performed a basic physical examination and collected urine samples for iodine determination. Parents were asked to answer a nutritional habits questionnaire.
Results: Eight hundred and sixty urine samples were obtained from 987 participants. Mean urinary iodine levels were 214.1 g/l (SD = 103.3 g/l) and the median was 189.0 g/l. Prevalence of iodine deficiency was 7.8% at a 100 g/l cut-off point and 1.2% at a 50 g/l cut-off point. Statistical differences in the prevalence of iodine deficiency were observed between ethnic groups: while natives had a prevalence of 7.0%, in Magrebins it was 18.4%, Subsaharians 20.0% and other ethnical groups 14.3% (p = 0.016).
Conclusions: Schoolchildren in Mataró have adequate urinary iodine levels according to WHO recommendations with a relatively low prevalence of iodine deficiency. However, even after adjustments for the knowledge of the existence of iodized salt, iodine deficiency correlates with the child's ethnic origin (native or immigrant).