Relationship between iodized salt and urinary iodine excretion in school children, Brazil

Abstract

To evaluate iodine parameters in iodized salt for human consumption and urine excretion of primary school children of two private and public schools. Urine samples of primary school students in a Southeastern urban area, Brazil, were collected, as well as samples of salt for human consumption used at their homes. Iodine level in urine and salt samples were measured to establish a correlation between the iodine concentration in the urine and salt samples. Mantel-Haenszel test was applied to measure the association between salt and urine. Urine iodine biochemical determinations were normal in 92.2% of private school children and 42.6% of public school children. The measurement of iodine in salt for human consumption showed that in 89.9% of public school and 40.9% of private school samples iodine was below the regulated levels. There was a statistically significant inverse association between the variable salt iodine and urine iodine. Iodine levels in salt for consumption were below the regulated by the Brazilian Health Ministry and there was also detected a significant iodine deficiency in the children's urine. Such levels were more drastically affected and were statistically more significant in public primary school children.