Scientific Opinion on Dietary Reference Values for iodine

Abstract

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for iodine, which are provided as Adequate Intake (AI). Iodine is essential for the synthesis of thyroid hormones. Through these hormones, iodine has an important role in energy-yielding metabolism and many other physiological processes. Iodine deficiency is associated with an increased frequency of goitre and hypothyroidism in a population. The AI for iodine is based on a large epidemiological study in European school-aged children showing that goitre prevalence is lowest for a urinary iodine concentration above around 100 µg/L. From this study, a urinary iodine concentration of ≥ 100 µg/L has been accepted as the threshold indicating sufficient iodine intake of school-aged children. In the absence of similar suitable data for other age groups it is proposed that this threshold also be applied for adults, infants and young children. Taking into account urinary volume and an absorption efficiency for iodine of 92 %, an AI of 150 µg/day is proposed for adults. For infants aged 7-11 months and for children, AIs range between 70 µg/day and 130 µg/day. For pregnant women, an AI of 200 µg/day is proposed, taking into account additional needs due to increased maternal thyroid hormone production and the iodine uptake by the fetus, placenta and amniotic fluid. The proposed AI for lactating women of 200 µg/day takes into account the existence of large iodine stores in conditions of adequate iodine status before pregnancy and considers that a full compensation for the iodine secreted in breast milk is not justified for the derivation of an AI for iodine for lactating women. Iodine is an essential nutrient for mammals, required as a mandatory structural and functional element of thyroid hormones. Through these hormones, iodine has an important role in energy-yielding metabolism and on the expression of genes that impact many physiological functions, including embryogenesis and growth, and the development of neurological and cognitive functions. © EuropeanThe clinical effects of iodine deficiency, referred to as iodine deficiency disorders, are the result of insufficient intakes leading to insufficient thyroid function. Iodine deficiency disorders are seen at all stages of development and are particularly of concern in pregnancy and infancy. Chronic iodine deficiency may lead to compensatory thyroid hypertrophy with an enlargement of the thyroid gland denoted as goitre.Intestinal absorption efficiency of ingested iodine is considered to be high (> 90 %). The thyroid is the major storage site for iodine in the body. Goitrogenous substances in foods, drinking water or cigarette smoke may inhibit the thyroidal uptake of iodide or its incorporation into the tyrosine precursors of thyroid hormones. The synthesis of normal quantities of thyroid hormones requires an adequate dietary intake of iodine. The kidney is the main route of excretion of iodine. In a steady state, th...

Scientific Opinion on the essential composition of infant and follow-on formulae

“…Average iodine concentrations of breast milk in Europe have been observed to be around 50-100 µg/L (8-15 µg/100 kcal) (Costeira et al, 2009;EFSA NDA Panel, 2014e).…”

“…In the Panel's previous opinion on nutrient requirements and dietary intakes of infants and young children in the European Union (EFSA NDA Panel, 2013a), the Panel concluded that an iodine intake of 90 µg/day is adequate for the majority of infants. Since there is no reason to assume that infants from birth to six months of age need more iodine than infants in the second half of the first year of life, the Panel considers, in line with its most recent evaluation (EFSA NDA Panel, 2014e), that an intake of iodine of 70 µg/day is adequate for the majority of infants from birth to 12 months of age.…”

Dietary Reference Values for nutrients Summary report

“…Iodine is an essential nutrient for mammals, required as a mandatory structural and functional element of thyroid hormones (EFSA NDA Panel, 2014g). Through these hormones, iodine has an important role in energy-yielding metabolism and on the expression of genes that impact many physiological functions, including embryogenesis and growth, and the development of neurological and cognitive functions.…”

Scientific Opinion on health benefits of seafood (fish and shellfish) consumption in relation to health risks associated with exposure to methylmercury

“…Adequate intakes of iodine (200 µg/day) have been estimated for pregnant and lactating women in order to accommodate the increased requirements for iodine (50 µg/day) during pregnancy and lactation (EFSA NDA Panel, 2014). In geographical areas where iodine intakes from other foods are insufficient, seafood consumption during pregnancy may have a major role in the development of the CNS of the foetus.…”

“…Among the essential nutrients contained in seafood in substantial amounts, DHA and iodine have a wellestablished role in the development of the central nervous system (CNS) of the foetus during pregnancy (EFSA NDA Panel, 2010a, 2014.…”