Background
Iodine deficiency has been recognised as a significant public health concern in Australia.1 Deficiency is of most concern in women planning pregnancy, given risks associated with poor neurological development in the baby. Following implementation of strategies to improve iodine intake at a population level, there has been minimal investigation into the current status of this problem.
Methods
Women of childbearing age attending outpatient clinics at Westmead Hospital, were asked to complete a questionnaire surveying dietary iodine intake as well as use of medications and recent IV radiological contrast exposure. A random single spot urine iodine was concurrently measured. The relationships between urine iodine level and dietary intake and use of iodine-containing multivitamins/ medications were examined.
Results
51 women completed the study. The median age was 30.4 (SD 6.9) years. The most represented ethnicities in the cohort were Caucasian 19/51(37.3%), Middle Eastern 13/51(25.5%), South East Asian and Indian Subcontinental both 8/51(15.7% in each group). The most commonly consumed source of dietary iodine was iodised salt 17/51(33.3%) used every day, followed by sliced bread 15/51(29.4%) used every day. 10/51(19.6%) used an iodine-containing multivitamin.
The median urine iodine level was 113ug/L (64,246) and 21/51 (41.2%) of women were iodine deficient (urine iodine <100ug/L). Half (5/10) of women taking iodine-containing multivitamins were iodine deficient. Excluding women on iodine-containing multivitamins and thyroxine, the median urine iodine level was 113ug/L (79,243). There was no statistically significant association between urine iodine and age or dietary iodine consumption (all spearman rank correlations <0.15 in absolute value). There was no significant association between urinary iodine levels and use of iodine-containing multivitamins or medications.
Conclusions
Despite public health strategies aimed at improving iodine intake, a significant proportion of women of childbearing age remain iodine deficient. Further research is needed to characterise this significant public health issue.