Iodine is a crucial trace mineral the body uses for the production of thyroid hormone, and without enough of it, a person can become hypothyroid. Most Americans don’t get a lot of iodine in their diet, in part because it’s present in foods we rarely consume, such as seaweed and fish. But we can get enough iodine in the daily diet by using iodized salt and by taking dietary supplements. Often, people choose to take high doses of iodine to support healthy thyroid function. However, we encourage people to take selenium when they take iodine.