History of Iodine Deficiency in Schoolchildren in Tasmania, Australia

This chapter reviews the history of iodine deficiency, supplementation and monitoring of school age children in the state. The history of iodine nutrition from 1949, when the first survey and supplementation program was undertaken, to the late 1980s when the population was considered to be iodine sufficient is reviewed. Details of the surveys conducted to confirm the re-emergence of iodine deficiency following a period without regular monitoring are presented. And the outcomes of a subsequent voluntary program of bread fortification and a series of post-fortification urinary iodine surveys are discussed. The re-emergence of deficiency coincided with a decline in iodine levels in milk at a time when milk was the major dietary source of iodine for the population. Voluntary fortification of bread has led to improved iodine nutrition in Tasmanian children, although girls remain borderline deficient. Reliance on a serendipitous and nonlegislated supply of iodine, as was the case with milk, is dangerous and can lead to a rapid return to deficiency when industry practices change. Mandatory fortification, preferably universal salt iodization, is required to eliminate iodine deficiency in all groups in the population. Ongoing monitoring of the population will help ensure that iodine nutrition is adequate and does not return to deficiency.