Prevalence of Iodine Deficiency in Infants and Young Children in Western Sydney, Australia

Iodine is an essential element required for the production of triiodothyronine and thyroxine. The absence of these hormones can cause numerous developmental defects, including irreversible mental retardation in infants and a loss of up to 13 intelligence quotient points in children. It has been reported that iodine deficiency has reemerged in Australians. In this study, random urinary iodine levels were measured in 106 infants and children of up to 5 years of age. The median urinary iodine concentration was 102 µg/L, but 47.2% of the population was below the World Health Organization—recommended level of 100 µg/L, ranging from mild (25.5%) to severe deficiency (6.6%). Of particular interest was the finding that children older than 2 years had significantly lower urinary iodine values (P = .02) than those in the 0- to 2-year age group. These results suggest inadequate dietary iodine intake in youth and point to the emergence of iodine deficiency as likely occurring from 2 years of age. They also support other Australian studies undertaken on older children and adults, as well as the need for a national iodine fortification program in Australia.