Iodine is added to salt primarily to prevent iodine deficiency in the population. Iodine is an essential micronutrient that the human body cannot produce on its own but needs for critical thyroid gland function, including hormone production that regulates metabolism, brain development, and overall growth. Deficiency in iodine can cause serious health issues like goiter (thyroid gland enlargement), intellectual disabilities, and developmental problems. Salt is used as the carrier for iodine because it is consumed by almost everyone daily, making it an effective and widely accessible vehicle to supply the essential nutrient. Adding iodine to salt is a cost-effective public health intervention that has drastically reduced iodine deficiency- related disorders in many countries since it was introduced around the 1920s. The iodine is added in the form of stable compounds like potassium iodide or potassium iodate, which do not affect the taste or appearance of the salt. This practice helps maintain adequate iodine levels in the diet, especially in regions where natural iodine levels in the soil and food supply are low.
