How Iodized Salt WorksYour thyroid is the only part of your body that requires iodine. After you ingest iodized salt, the iodine enters your gastrointestinal tract. Then proteins transport the iodine to follicular cells within the thyroid gland, according to California State University. Inside the follicles, the iodine undergoes an oxidation process necessary for T3 triiodothyronine and T4 thyroxine hormone production. Your pituitary gland, a tiny gland located at the base of your brain, controls how much of these hormones your body needs, and your thyroid responds accordingly.