Iodine

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 150–250 µg/d. 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). Globally, it is estimated that two billion individuals have an insufficient iodine intake, many in low-middle income countries. Iodine deficiency early in life impairs 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.