Iodine Deficiency Disorders and Their Correction Using Iodized Salt and/or Iodine Supplements

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 intake for healthy adults is 150–250 μg day-1. 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 (IDD). 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. Assessment methods include urinary iodine concentration (UIC), goiter, newborn thyrotropin (TSH), and blood thyroglobulin. In most countries, the best strategy to control iodine deficiency in populations is iodization of salt, one of the most cost-effective ways to contribute to economic and social development.