Using bread as a vehicle to improve the iodine status of New Zealand children.
OBJECTIVE
To determine the iodine status of a sample of Dunedin school children, and to estimate how the addition of iodised salt to bread will improve their iodine status.


METHODS
Between October and November 2007, iodine status in a sample of 93 Dunedin school children was assessed by urinary iodine concentration (UIC), serum thyroglobulin (Tg), and dietary iodine intake, estimated using an iodine-specific food frequency questionnaire. Data from the 2002 National Children's Nutrition Survey and the New Zealand Food Composition Database were used to calculate the increase in total dietary iodine intake if bread is made with iodised salt, and subsequently, the predicted increase in UIC.


RESULTS
Both the median UIC of 63 mcg/L (interquartile range (IQR) 44-78 mcg/L) and the median serum Tg concentration of 14 mcg/L (IQR 10-23 mcg/L) classify this sample of children as mildly iodine deficient. The estimated dietary iodine intake was 54 mcg/day (IQR 41-65 mcg/L), which is well below the estimated average requirement (EAR) of 75 mcg/day; 83% of children in this study were found to have iodine intakes below the EAR. The addition of iodised salt to bread would increase the average iodine intake of these children to 75-104 mcg/day, thus decreasing the number of children who have an iodine intake less than the EAR to 4-46%. Consequently, the median UIC of these children would increase to 95-151 mcg/L.


CONCLUSIONS
The introduction of iodised salt to bread, which is currently scheduled to become mandatory in September 2009, should improve the iodine status of New Zealand children. The use of iodised salt in other bakery products is encouraged to maximise this improvement.
Rose
Meredith
M
Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
Gordon
Rosie
R
Skeaff
Sheila
S