This study confirms recent studies of iodine nutrition in children and pregnant women performed by measuring iodine excretion in the urine and thyroid size by ultrasound.
Steps are being taken to address this problem, including the mandatory fortification of bread with iodised salt from September 2009, but one expert says it will not solve the problem.
Professor Creswell Eastman, Director of the Australian Centre for Iodine Deficiency Disorders, says, "while I applaud the fact that iodine deficiency in Australia has been formally recognised, and support the efforts of the Australian government in taking positive steps in order to help resolve the deficiency, some groups such as pregnant and breast-feeding women and those who do not or cannot eat bread will simply not obtain enough iodine from diet alone, even if foods are fortified."
If women don't get enough iodine there are many serious side effects. For pregnant women, the thyroid will not make enough thyroid hormones and the baby's brain may not get enough thyroid hormone.
Eastman went on to explain that children born of moderately to severely iodine-deficient mothers have lower IQs. They may lose 5 to 15 IQ points, have hearing difficulties, learning and behavioural difficulties, and ultimately have an overgrown thyroid gland as they grow up.
"If you are planning to fall pregnant, or you are already pregnant or breast-feeding, then you should consider taking a supplement with iodine," said Eastman.
References available on request