Iodine and Iodine Deficiency Disorders

Iodine is an essential component of hormones produced by the thyroid gland. Thyroid hormones, and therefore iodine, are essential for mammalian life. Optimal dietary iodine intakes for healthy adults are 150-250μg/day. In regions where iodine in soils and drinking water is low, humans and animals may become iodine deficient. Iodine deficiency has multiple adverse effects in humans due to inadequate thyroid hormone production that are termed the iodine deficiency disorders. Assessment methods for iodine deficiency include urinary iodine concentration, goiter, newborn thyroid-stimulating hormone, and blood thyroglobulin. Globally, it is estimated that 2 billion individuals have an insufficient iodine intake, many in developing countries. However, iodine deficiency also affects industrialized countries: ~50% of continental Europe remains mildly iodine deficient, and iodine intakes in other industrialized countries, including the United States, the United Kingdom and Australia, have fallen sharply in recent years. Iodine deficiency during pregnancy and infancy may impair growth and neurodevelopment of the offspring and increase infant mortality. Deficiency during childhood reduces somatic growth and cognitive and motor function. In most countries, the best strategy to control iodine deficiency in populations is carefully monitored iodization of salt, one of the most cost-effective ways to contribute to economic and social development. © 2012 International Life Sciences Institute.