Iodine status of Tasmanians following voluntary fortification of bread with iodine.
OBJECTIVE
To describe changes in the iodine status of Tasmanians following voluntary fortification of bread with iodine in October 2001.


METHODS
Post-intervention, cross-sectional urinary iodine surveys of Tasmanian schoolchildren aged 8-11 years were used to assess population iodine status. Participants were selected using a one-stage cluster sampling method. The sampling frame comprised classes containing fourth-grade children from all Tasmanian government, Catholic and independent schools. Results were compared with pre-intervention survey results.


METHODS
Median urinary iodine concentration (UIC) and percentage of UIC < 50 microg/L ascertained from spot urine samples.


RESULTS
Median UIC was 75 microg/L in 1998, 72 microg/L in 2000, 105 microg/L in 2003, 109 microg/L in 2004 and 105 microg/L in 2005. Median UIC in post-intervention years (2003-2005) was significantly higher than in pre-intervention years. The percentage of UIC results < 50 microg/L was 16.9% in 1998, 18.7% in 2000, 10.1% in 2003, 10.0% in 2004 and 10.5% in 2005.


CONCLUSIONS
Despite methodological differences between the pre- and post-intervention surveys, switching to iodised salt in bread appears to have resulted in a significant improvement in iodine status in Tasmania. Given iodine deficiency has been identified in other parts of Australia and in New Zealand, mandatory iodine fortification of the food supply in both countries is worthy of consideration. As voluntary fortification relies on industry goodwill, mandating fortification could be expected to enhance population reach and give a greater guarantee of sustainability in Tasmania.
Seal
Judy A
JA
Public and Environmental Health Service, Department of Health and Human Services, Hobart, Tasmania, Australia. judy.seal@dhhs.tas.gov.au
Doyle
Zelda
Z
Burgess
John R
JR
Taylor
Roscoe
R
Cameron
Angus R
AR
D001939:Bread; D002648:Child; D003430:Cross-Sectional Studies; D005527:Food, Fortified; D006801:Humans; D007455:Iodine / Q000008:administration & dosage* / Q000172:deficiency / Q000652:urine*; D013648:Tasmania
D007455:Iodine