Iodine is an important micronutrient, a vitamin or mineral that is necessary for good health. It helps the body to produce hormones, helps babies develop in the womb, and is important to many other body processes. In 1924, iodine was added to salt to make up for a lack of public access to dairy foods and ocean fish, which are natural sources of iodine. The modern American diet, however, includes many processed foods that contain iodine. As a result, many salt manufacturers have stopped adding iodine to their product, a change that did not get much attention in the media. Some nutrition experts are concerned that people who still rely on table salt as a source of iodine will have an increase in disease caused by a diet lacking in this micronutrient. Only time will tell, as America moves into a new era where table salt is no longer a guaranteed source of iodine. Why does iodine matter to nutrition experts?