Several substances are known to disrupt iodide uptake, including perchlorate, thiocyanate, and certain classes of pesticides. Perchlorate, for instance, competes with iodide for uptake by the NIS, thereby reducing the availability of iodide for thyroid hormone production. Similarly, thiocyanate, found in cigarette smoke and certain foods, can inhibit iodide transport, especially in populations with low iodine intake.
