Iodine Malnutrition and Associated Factors in Schoolchildren Aged 6 to 14 Years in a Municipality Situated in the Semi-Arid Region of the State of Minas Gerais, Brazil, 2008

Abstract

The objective of this study was to assess the prevalence of iodine deficiency and possible correlated factors among schoolchildren in the municipality of Novo Cruzeiro-MG by means of an evaluation of urinary iodine excretion. Five hundred and forty schoolchildren aged 6 to 14 years selected by stratified sampling, were evaluated. Urine samples were analyzed using the Sandell-Kolthoff method preconized by the WHO and iodine concentrations in the salt were assessed by means of volumetric analysis, in accordance with recommendations from the Ministry of Health. Iodine deficiency was observed in 38.9% of the schoolchildren. Of these, 28.7% of them presented slight deficiency, 6.2% of them were moderately deficient and 4% of them were seriously deficient. Median urinary iodine levels in the urban and rural population were 150.8 and 119.2 µg/L, respectively, with a clear distribution of iodine deficiency among the populations (p<0.001) being registered. It was also observed that there was a high prevalence of deficient urinary iodine excretion among schoolchildren that consumed salt with an insufficient iodine content. In relation to the quality of the salt consumed by families, in 12.2% of the residences studied the iodine content in salt was below the recommended level (20 mg/kg), while the iodine content was below 15 mg/kg in only 5.3% of them. The results indicated that, although not characterized as a public health issue, according to WHO criteria, iodine deficiency showed very high prevalence among schoolchildren in this region. Regarding the iodine content of salt found in household consumption, our findings indicated the National Program of Salt Iodination was not efficient in the city, since it did not hit the target proposed by the Ministry of Health. Furthermore, low urinary iodine excretion associated with the consumption of salt with low iodine content suggests the need for periodical evaluations in order to provide effective control of the endemic disease.