An evaluation of the iodine status of the Riverina, 2004

This study assessed the iodine status of a random group of adults in a rural region. Urinary iodine concentrations (UIC) were correlated with results of a questionnaire that collected demographic information. 173 adults from the Riverina region provided a morning mid-stream urine sample and completed a questionnaire. Iodine status was based upon median UIC values and categorised according to WHO criterion. Subgroups were classified according to sex, age, town, salt usage, and vitamin/supplement usage. The median UIC (MUIC) for the study population was 79µg/L and 71.1% had a concentration less than 100µg/L, consistent with a mild iodine deficiency. 18.5% were moderately to severely deficient (UIC of less than 50µg/L). 41% used iodised salt but those subjects did not have a significantly higher UIC (81µg/L) than those not using iodised salt (71µg/L). Those that consumed vitamin supplements containing iodine on a regular basis had a significantly higher UIC (111µg/L) than those that did not (77µg/L). Participants aged 50-59 years had a significantly lower UIC than participants aged 18-39 years (67µg/L vs. 89µg/L respectively). Further, MUIC decreased with age from18 to 59. A mild iodine deficiency was found in this sample of the Riverina population, consistent with other Australian studies that suggest the recurrence of iodine deficiencies in this country. Salt iodisation may not be an effective strategy to correct iodine deficiencies within Australia.