Following an application from Specialised Nutrition Europe (formerly IDACE), submitted pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of France, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to iodine and contribution to normal thyroid function. The food constituent, iodine, which is the subject of the health claim, is sufficiently characterised. Contribution to normal thyroid function is a beneficial physiological effect for infants and young children. A claim on iodine and normal thyroid function in the general population has already been assessed with a favourable outcome. The Panel considers that the role of iodine on normal thyroid function applies to all ages, including infants and young children (from birth to three years). The Panel concludes that a cause and effect relationship has been established between the dietary intake of iodine and contribution to normal thyroid function.