iodized

Iodized is an adjective used to describe substances in which iodine has been added. In nutrition and public health, iodization refers to the deliberate addition of iodine to food or other goods to prevent iodine deficiency disorders (IDD). The most common application is iodized salt, produced by adding a small amount of iodine as potassium iodide or potassium iodate to table salt. The resulting product provides iodine intake with meals without requiring changes in behavior.

Levels vary by country, but typical iodization rates are in the tens of milligrams of iodine per kilogram of salt (parts per million). Iodine is essential for thyroid hormone production, which supports growth, metabolism, and neurodevelopment.

Public health programs began widespread use of iodized salt in the 20th century and have contributed to declines in IDD, particularly in regions where soils are iodine-poor. The approach is generally safe when iodization levels are appropriate, though excessive intake or preexisting thyroid conditions can cause thyroid dysfunction. In many places, iodized salt is labeled to indicate its content; non-iodized salt remains available for those who need to limit iodine intake.

Storage: iodine can slowly degrade with heat and humidity; iodized salt is typically stored in cool, dry, sealed containers to preserve iodine content.