IODINE

Iodine is an essential nutrient required for the production of thyroid hormones. These hormones are important for normal growth and development, particularly of the brain. The major dietary sources of iodine include seafood, especially seaweed, baked bread and dairy milk. Inadequate amounts of iodine may lead to a range of conditions, including goiter, hypothyroidism, and in severe cases, intellectual disability.¹

Data source and definitions Iodine levels are measured using a urine test. According to the World Health Organization (WHO), a population is considered iodine deficient if the median urinary iodine concentration (MUIC) is less than 100 μg/L. The WHO recommends that no more than 20% and 50% of the population have an iodine concentration below 50 μg/L and 100 μg/L, respectively.1

The National Aboriginal and Torres Strait Islander Health Measure Survey (NATSIHMS) showed that the Aboriginal and Torres Strait Islander adult population was iodine sufficient in 2012–13, with a population MUIC of 135.0 μg/L. Likewise, only around one in ten people (10.8%) had an iodine level of less than 50 μg/L.

Overall, Aboriginal and Torres Strait Islander adults had higher iodine levels than all non-Indigenous adults (a median of 135.0 ug/L compared with 124.0 ug/L).² Likewise, after adjusting for age differences, Aboriginal and Torres Strait Islander people were less likely than non-Indigenous people to have iodine levels under 50 μg/L (rate ratio 0.8).

Median iodine levels were generally higher among Aboriginal and Torres Strait Islander people living in remote areas than in non-remote areas in 2012–13. This may be due to the varying access to and affordability of certain foods, or the different diets typically consumed by people living in various parts of Australia. Interestingly, however, there was no difference in proportion of people with an iodine level of less than 50 μg/L between non-remote and remote areas (11.0% compared with 10.1%).

Looking at age, rates of urinary iodine concentration below 50 ug/L remained fairly stable among Aboriginal and Torres Strait Islander and non-Indigenous adults across all broad age groups. Although rates for both populations appeared to dip for those aged 55 years and over, this difference was not significant.



Sufficient iodine levels are particularly important for women of childbearing years as deficiency could impede the normal growth and development of the fetus if these women were to become pregnant.¹ In 2012–13, Aboriginal and Torres Strait Islander women aged 18–44 years had a MUIC of 135 μg/L, which was above the recommended population level of 100 ug/L.

For more information on iodine, see Tables 2, 3, 4 and 5 on the Downloads page of this publication.



ENDNOTES

1 World Health Organization, UNICEF, ICCIDD, 2007, Assessment of iodine deficiency disorders and monitoring their elimination, <http://www.who.int/nutrition/publications/micronutrients/iodine_deficiency/9789241595827/en/>,
2 Australian Bureau of Statistics 2014, Australian Health Survey: Biomedical Results for Nutrients, 2011-12, ABS cat. no. 4364.0.55.006, <https://www.abs.gov.au/ausstats/abs@.nsf/Lookup/4364.0.55.006Chapter2002011-12>, Back to top