Food sources of iodine in schoolchildren and relationship with 24-h urinary iodine excretion in Victoria, Australia

Abstract

Dietary recalls have been used previously to identify food sources of iodine in Australian schoolchildren. Dietary assessment can provide information on the relative contributions of individual food groups which can be related to a robust objective measure of daily intake (24hr urinary iodine excretion (UIE)). In Australia, the government has mandated the use of iodised salt in breadmaking to address iodine deficiency. The aim of this study was to determine the dietary intake and food sources of iodine to assess their contribution to iodine excretion (UIE) in a sample of Australian schoolchildren. In 2011-13 UIE was assessed using a single 24-hour urine sample and dietary intake was assessed using one 24-hour dietary recall in a convenience sample of primary schoolchildren from schools in Victoria, Australia. Of the 454 children with a valid recall and urine sample 55% were male (average age 10.1) (1.3(SD) years). Mean (SD) UIE and dietary iodine intake were 108(54) and 172(74) μg/day, respectively. Dietary assessment indicated that bread and milk were the main food sources of iodine, contributing 27% and 25%, respectively, to dietary iodine. Milk but not bread intake was positively associated with UIE. Multiple regression (adjusted for school cluster, age and gender) indicated that for every 100g increase in milk consumption, there was a 3μg/day increase in UIE (β=4.0 (0.9)(SE), P<0.001). In conclusion, both bread and milk were important contributors to dietary iodine intake however consumption of bread was not associated with daily iodine excretion in this group of Australian schoolchildren.

Iodine intake assessment in the staff of a Porto region university (Portugal): the iMC Salt trial

“…Taking the average bread consumption, the aimed value for salt in its production, and the average iodine content in salt found in this study, bread alone can represent a daily iodine intake of nearly 18 µg (12.2% of the daily requirement). Strategies of using iodized salt in bread production have been successfully applied to increase iodine intake adequacy elsewhere [ 47 , 48 ]. The contribution to the daily iodine intake of fruits, vegetables, and legumes observed in this study is in line with the previously reported iodine content of Portuguese foods [ 18 ] and already demonstrated in the literature [ 49 , 50 ].…”

Iodine Intake, UIE Levels, Nutritional Status and Academic Achievements in School-Age Children in Magelang, Central Java

“…Urinary Iodine Excretion (UIE) is an indicator of iodine status, because most of the iodine absorbed by the body will be excreted in the urine and can reflect current iodine intake and recent changes in a person's iodine status (Campanozzi et al, 2019). Examination of UIE a sensitive marker to determine a long-term effect of iodine intake for months to years (Beckford et al, 2022). Adequate intake of iodine can increase complete brain development at the age of 7 years until 15 (Murcia et al, 2018).…”