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The role of iodine in brain development

Published online by Cambridge University Press:  28 February 2007

François Delange*
Affiliation:
International Council for Control of Iodine Deficiency Disorders, 153 Avenue de la Fauconnerie, B-1170 Brussels, Belgium
*
*Corresponding author: Professor F. Delange, fax +32 2 675 18 98, email fdelange@ulb.ac.be
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Abstract

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I is required for the synthesis of thyroid hormones. These hormones, in turn, are required for brain development, which occurs during fetal and early postnatal life. The present paper reviews the impact of I deficiency (1) on thyroid function during pregnancy and in the neonate, and (2) on the intellectual development of infants and children. All extents of I deficiency (based on I intake (μg/d); mild 50–99, moderate 20–49, severe > 20) affect the thyroid function of the mother and neonate, and the mental development of the child. The damage increases with the extent of the deficiency, with overt endemic cretinism as the severest consequence. This syndrome combines irreversible mental retardation, neurological damage and thyroid failure. Maternal hypothyroxinaemia during early pregnancy is a key factor in the development of the neurological damage in the cretin. Se deficiency superimposed on I deficiency partly prevents the neurological damage, but precipitates severe hypothyroidism in cretins. I deficiency results in a global loss of 10–15 intellectual quotient points at a population level, and constitutes the world’s greatest single cause of preventable brain damage and mental retardation.

Type
Micronutrient Group Symposium on ‘The role of micronutrients as modulators of development’
Copyright
Copyright © The Nutrition Society 2000

References

Aghini-Lombardi, F, Pinchera, A, Antonangeli, L, Rago, T, Chiovato, L, Bargagna, S, Bertucelli, B, Ferretti, G, Sbrana, B, Marcheschi, M & Vitti, P (1995) Mild iodine deficiency during fetal/neonatal life and neuropsychological impairment in Tuscany. Journal of Endocrinological Investigation 18, 5762.Google Scholar
Bernal, J & Nunez, J (1995) Thyroid hormones and brain development. European Journal of Endocrinology 133, 390398.Google Scholar
Bleichrodt, N & Born, MP (1994) A metaanalysis of research on iodine and its relationship to cognitive development. In The Damaged Brain of Iodine Deficiency, pp. 195200 [Stanbury, JB, editor]. New York: Cognizant Communication.Google Scholar
Boyages, SC & Halpern, JP (1993) Endemic cretinism: toward a unifying hypothesis. Thyroid 3, 5969.Google Scholar
Burrow, GN (1972) The Thyroid Gland in Pregnancy. Philadelphia, PA: Saunders.Google Scholar
Choufoer, JC, Van Rhijn, M & Querido, A (1965) Endemic goiter in Western New Guinea. II. Clinical picture, incidence and pathogenesis of endemic cretinism. Journal of Clinical Endocrinology and Metabolism 25, 385402.Google Scholar
Contempré, B, Dumont, JE, Bebe, N, Thilly, CH, Diplock, AT & Vanderpas, J (1991) Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine deficient subjects with selenium. Journal of Clinical Endocrinology and Metabolism 73, 213215.Google Scholar
Delange, F (1994) The disorders induced by iodine deficiency. Thyroid 4, 107128.CrossRefGoogle ScholarPubMed
Delange, F (1998) Screening for congenital hypothyroidism used as an indicator of IDD control. Thyroid 8, 11851192.CrossRefGoogle Scholar
Delange, F (2000) Endemic cretinism. In The Thyroid. A Fundamental and Clinical Text, 8th ed. [Braverman, LE and Utiger, RD, editors]. Philadelphia, PA: Lippincott. (In the Press).Google Scholar
Delange, F, Bourdoux, P, Ketelbant-Balasse, P, Van Humskerken, A, Glinoer, D & Ermans, AM (1983) Transient primary hypothyroidism in the newborn. In Congenital Hypothyroidism, pp. 275301 [Dussault, JH and Walker, P, editors]. New York: M. Dekker.Google Scholar
Delange, F, Bourdoux, P, Laurence, M, Peneva, L, Walfish, P & Willgerodt, H (1993) Neonatal thyroid function in iodine deficiency. In Iodine Deficiency in Europe. A Continuing Concern, pp. 199210 [Delange, F, Dunn, JT and Glinoer, D, editors]. New York: Plenum Press.Google Scholar
Delange, F, Iteke, FB & Ermans, AM (1982) Nutritional Factors Involved in the Goitrogenic Action of Cassava. Ottawa, Ont.: International Development Research Centre.Google Scholar
De, Long G, Robbins, J & Condliffe, PG (1989) Iodine and the Brain. New York: Plenum Press.Google Scholar
Fierro-Benitez, R, Ramirez, I, Estrella, E & Stanbury, JB (1974) The role of iodine deficiency in intellectual development in an area of endemic goiter. In Endemic Goiter and Cretinism: Continuing Threats to World Health Pan American Health Organization Publication no. 292, pp. 135142 [Dunn, J and Medeiros-Neto, GA, editors]. Washington, DC: Pan American Health Organization.Google Scholar
Fisher, DA & Klein, AH (1981) Thyroid development and disorders of thyroid function in the newborn. New England Journal of Medicine 304, 702712.Google Scholar
Glinoer, D (1997a) The regulation of thyroid function in pregnancy: pathways of endocrine adaptation from physiology to pathology. Endocrine Reviews 18, 404433.Google Scholar
Glinoer, D (1997b) Maternal and fetal impact of chronic iodine deficiency. Clinical Obstetrics and Gynecology 40, 102116.CrossRefGoogle ScholarPubMed
Glinoer, D, De, Nayer P, Delange, F, Toppet, V, Spehl, M, Grun, JP, Kinthaert, J & Lejeune, B (1995) A randomized trial for the treatment of excessive thyroid stimulation in pregnancy: maternal and neonatal effects. Journal of Clinical Endocrinology and Metabolism 80, 258269.Google ScholarPubMed
Hetzel, BS (1983) Iodine deficiency disorders (IDD) and their eradication. Lancet ii, 11261129.Google Scholar
Morreale, de Escobar G, Obregon, MJ, Calvo, R, Pedraza, P & Escobar, del Rey F (1997) Iodine deficiency, the hidden scourge: the rat model of human neurological cretinism. In Neuroendocrinology, pp. 5570 [Hendrich, CH, editor]. Trivandrum, India: Research/Signpost.Google Scholar
Obregon, MJ, Calvo, RM, Escobar, del Rey F & Morreale, de Escobar G (1998) Thyroid hormones and fetal development. In The Thyroid and Age, pp. 4973 [Pinchera, A, Mann, K and Hostalek, U, editors]. Stuttgart: Schattauer.Google Scholar
Pharoah, POD, Connolly, KJ, Ekins, RP & Harding, AG (1984) Maternal thyroid hormone levels in pregnancy and the subsequent cognitive and motor performance of the children. Clinical Endocrinology 21, 265270.CrossRefGoogle ScholarPubMed
Rajatanavin, R, Chailurkit, L, Winichakoon, P, Mahachoklertwattana, P, Soranasataporn, S, Wacharasin, R, Chaisongkram, V, Amatyakul, P & Wanarata, L (1997) Endemic cretinism in Thailand: a multidisciplinary survey. European Journal of Endocrinology 137, 349355.CrossRefGoogle ScholarPubMed
Stanbury, JB (1994) The Damaged Brain of Iodine Deficiency. New York: Cognizant Communication.Google Scholar
Stanbury, JB, Delange, F, Dunn, JT & Pandav, CS (1998) Iodine in Pregnancy. New Delhi: Oxford University Press.Google Scholar
Thilly, CH, Delange, F, Lagasse, R, Bourdoux, P, Ramioul, L, Berquist, H & Ermans, AM (1978) Fetal hypothyroidism and maternal thyroid status in severe endemic goiter. Journal of Clinical Endocrinology and Metabolism 47, 354360.CrossRefGoogle ScholarPubMed
Vanderpas, JB, Contempré, B, Duale, NL, Goossens, W, Bebe, N, Thorpe, R, Ntambue, K, Dumont, J, Thilly, CH & Diplock, AT (1990) Iodine and selenium deficiency associated with cretinism in Northern Zaire. American Journal of Clinical Nutrition 52, 10871093.Google Scholar
Van, Vliet G (1998) Treatment and outcome of neonatal hypothyroidism. In The Thyroid and Age, pp. 109120 [Pinchera, A, Mann, K and Hostalek, U, editors], Stuttgart: Schattauer.Google Scholar
Vermiglio, F, Lo Presti, VP, Scaffidi Argentina, G, Finocchiaro, MO, Gullo, D, Squatrito, S & Trimarchi, F (1995) Maternal hypothyroxinemia during the first half of gestation in an iodine deficient area with endemic cretinism and related disorders. Clinical Endocrinology 42, 409415.Google Scholar
Vulsma, T (1998) Transplacental transfer of thyroid hormones. In The Thyroid and Age, pp. 3948 [A, Pinchera, K, Mann and U, Hostalek, editors]. Stuttgart: Schattauer.Google Scholar
World, Health Organization (1996) Iodine. Trace Elements in Human Nutrition and Health, pp. 4971.Geneva: WHO.Google Scholar
World Health Organization/United Nations for Children's Fund/ International Council for Control of Iodine Deficiency Disorders (1994) Indicators for Assessing Iodine Deficiency Disorders and their Control Through Salt Iodization. WHO/NUT/94.6. Geneva: WHO.Google Scholar