Improved iodine status in Tasmanian schoolchildren after fortification of bread: a recipe for national success
Iodine is an essential micronutrient required for thyroid hormone synthesis. Inadequate dietary iodine intake is associated with a spectrum of diseases termed iodine deficiency disorders. The most serious and overt consequences are neurocognitive disorders and endemic goitre.1 Urinary iodine excretion is a marker of recent dietary iodine intake and is typically used to monitor population iodine sufficiency. Population iodine status is considered optimal when median urinary iodine concentration (UIC) is between 100 µg/L and 199 µg/L, with no more than 20% of samples having UIC under 50 µg/L.1
Concern about the emergence of widespread mild iodine deficiency in Australia and New Zealand led to mandatory iodine fortification of yeast-leavened bread in 2009.2 Tasmania has a well documented history of endemic iodine deficiency, with iodine supplementation strategies implemented since the 1950s.3 The use of iodophors as sanitising agents in the dairy industry was thought to have provided protection; however, urinary iodine surveys of Tasmanian school children in 1998 and 2000 showed a recurrence of iodine deficiency.