The effect of iodine supplementation on cognition in school-aged children

INTERVENTION: A flavoured, chewable tablet containing 120 micrograms of iodine to be taken daily for 28 weeks CONDITION: Iodine deficiency PRIMARY OUTCOME: Cognitive performance will be assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB) SECONDARY OUTCOME: Iodine status and thyroid status will be assessed by the measurement of urinary iodine concentrations, thyroglobulin, free thyroxine, and thyrotropin levels. Nutritional status will be assessed by a Food Frequency Questionnaire: The Australian Child and Adolescent Eating Survey Use of iodized or non‐iodized salt at home will be assessed by a Type of Salt Used at Home Checklist INCLUSION CRITERIA: Mildly iodine‐deficient (i.e., a median urinary iodine concentration level of 50‐99 micrograms per litre in the study population) No history of thyroid disease Not taking iodine‐containing supplements