Re‐emergence of iodine deficiency in Australia

Abstract

Iodine is an essential nutrient for human growth and development. The thyroid gland is dependent upon iodine for production of thyroid hormone. It is a common perception that iodine deficiency is not a major public health concern in mainland Australia, with sporadic studies carried out about a decade ago showing average urinary iodine excretion levels of around 200 microg/day. Recent evidence, however, has shown that the consumption of iodine is declining in Australia. A similar situation has occurred in the USA. The present study was designed to evaluate the urinary iodine excretion (UIE), as the indicator of iodine nutrition, in samples obtained from various demographic groups in the Sydney metropolitian area, namely: schoolchildren, healthy adult volunteers. pregnant women and patients with diabetes. Urinary iodine in spot urine sample was measured in a Technicon II autoanalyser using an in-house, semiautomated method. The results in this communication show that all four study groups had the median UIE below 100 microg/L. the criteria set by the World Health Organization for iodine repletion, and confirm what has been described previously, that iodine deficiency has reemerged in Sydney, Australia. One of the major causes of the reduced iodine intake is the reduction of iodine in milk since the dairy industry replaced iodine-rich cleaning solutions with other sanitisers. Secondly, less than 10% of the population are currently using iodised salt. A national survey into the iodine nutrition status in Australia is urgently required as part of the establishment of a systematic surveillance and legislation is required to iodise all edible salt.

Iodine Deficiency in Pregnant Women Pre- and Post-Mandatory Iodine Fortification in Australia - An Epidemiological Review

“…Children in Western Australia and Queensland were found to be iodine replete by comparison. The results from NSW and Victoria were very similar to those previously reported [27][28][29].…”

“…72% of a sample of pregnant women in Western Sydney were iodine deficient, with 32% suffering from moderate deficiency [30]. The MUIC of 81 μg/L was similar to the level found in a pregnant population in Sydney approximately 10 years prior indicating that the situation had not improved despite publicity in the medical and lay press about iodine deficiency [27]. Similar reports of iodine deficiency from Victoria and Tasmania indicate the degree of iodine deficiency in pregnant women (52 μg/L) was even worse than in NSW [11,18].…”

Mild iodine deficiency in a sample of New Zealand schoolchildren

“…These results support those of Thomson et al (1997), who found mild IDD in New Zealand adults. A recent study in Sydney, Australia also found mild IDD as determined by casual urine samples in school-aged children (Li et al, 2001). A prevalence of thyroid volume > ULN between 5 and 20% of children is suggested by WHO=ICCIDD=UNICEF to be indicative of mild IDD (WHO et al, 1994).…”

Dairy food intake of Australian children and adolescents 2–16 years of age: 2007 Australian National Children's Nutrition and Physical Activity Survey

“…The mean amount of iodine provided by MPD in 2007 was somewhat greater than this (56-93 mg iodine); nevertheless, the proportion contributed to total iodine intake from dairy foods is expected to have fallen due to the additional intake from fortified bread. Also, the iodine concentration of milk is variable (18) and may be influenced by production methods.…”