URINARY IODINE CONCENTRATIONS IN SWISS SCHOOLCHILDREN FROM THE ZURICHAREA AND THE ENGADINE VALLEY

To prevent iodine deficiency disorders in Switzerland, table salt is c urrently fortified at 15 mg iodide/kg salt. However, several recent re ports have suggested that urinary iodine excretion is marginal or inad equate among segments of the Swiss population, including schoolchildre n. There is concern that iodine intake in Switzerland may be approachi ng levels associated with signs of clinical deficiency. Previous studi es measuring urinary iodine in Swiss children have encompassed only a limited geographic area in central Switzerland. We have now evaluated urinary iodine concentrations in 243 schoolchildren aged 5 to 13 years from the Zurich area and the Engadine valley. The mean urinary iodine for all children was 11.3+/-8.7 mu g/dl. There was no significant dif ference between iodine levels in urine from children in the Engadine a nd those from around Zurich. There were also no significant gender dif ferences in urinary iodine concentrations. The median urinary iodine c oncentration for all children was 9.6 mu g/dl, below the threshold sug gested by the World Health Organization (<10 mu g/dl) as indicative of mild iodine deficiency. 54.3% of the children had urinary iodine conc entrations <10 mu g/dl and 11.5% had levels <5 mu g/dl. The results of this study suggest that the iodine status of some Swiss schoolchildre n may no longer be adequate. They indicate the importance of intermitt ent monitoring of iodine status in Switzerland, where dietary habits a nd food supply patterns are changing. They also support the recent dec ision (February 1998) by the Swiss Federal Department of the Interior to increase the concentration of iodide in Swiss table salt, based on the recommendations of the Fluoride-Iodine Commission of the Swiss Aca demy of Medical Sciences.