iodine deficiency currently affects around 2 billion people and is the leading preventable cause of intellectual disability.

Iodine deficiency is a lack of the trace element iodine. It may result in goiter (so-called endemic goiter), as well ascretinism, which results in developmental delays and other health problems. Iodine deficiency is an important public health issue as it is a preventable cause of intellectual disability.

Iodine is an essential trace element; the thyroid hormones thyroxine and triiodothyronine contain iodine. In areas where there is little iodine in the diet, typically remote inland areas where no marine foods are eaten, iodine deficiency is common. It is also common in mountainous regions of the world where food is grown in iodine-poor soil.

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Prevention includes adding small amounts of iodine to table salt, a product known as iodized salt. Iodine compounds have also been added to other foodstuffs, such as flour, water and milk, in areas of deficiency.[1] Seafood is also a well known source of iodine.[2]

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