Ioduria and iodine concentration in table salt in Peruvian elementary schoolchildren

Abstract

Objectives. To determine the ioduria and iodine concentration in table salt in Peruvian elementary schoolchildren. Materials and methods. A cross-sectional study was performed. A total of 8,023 elementary schoolchildren, who voluntarily participated, were included. Multistage stratified probability sampling was performed, and the sample was obtained by
systematic selection. Ioduria was determined via spectrophotometry (Sandell-Kolthoff method), and the amount of iodine in salt was evaluated volumetrically. The data were processed by means of analysis for complex samples with a weighting factor. Medians, percentiles, and confidence intervals were calculated, and the Mann-Whitney U and Kruskal-Wallis H tests were used, where appropriate. Results. Nationwide, the median ioduria in schoolchildren was 258.53 ug/L, being higher in boys (265.90 ug/L) than in girls (250.77 ug/L). The median ioduria in urban areas was higher (289.89 ug/L) than that in rural areas (199.67 ug/L), while it was 315.48 ug/L in private schools and 241.56 ug/L in public schools (p<0.001). The median iodine concentration in table salt was 28.69 mg/kg. Of the total salt samples, 23.1% contained less than 15 mg/kg of iodine. Conclusions. The median ioduria in elementary schoolchildren exceeded normal levels, according to the criteria of the World Health Organization, with differences between urban and rural areas and public and private schools.