Side Effects of Iodine Supplements

Iodine, a trace mineral, plays an essential part in the manufacture of thyroid hormones by the thyroid gland. The thyroid gland contains most of the body's iodine stores. If you have an iodine deficiency, you may develop hypothyroidism, or low thyroid levels, with weight gain, lethargy and enlargement of the thyroid gland. Iodine deficiency rarely occurs in the United States since all table salt is fortified with iodine and most people ingest adequate amounts of sodium. Supplements can be injected or taken by mouth. Taking iodine supplements can cause side effects, some of which are serious. Never take iodine supplements without medical supervision.

Oral Effects

If you take iodine supplements in an oral liquid, dilute the drug in juice or milk, because this will reduce the bitter taste. Sipping the mixture through a straw helps minimize the burning in the mouth that can occur while taking iodine supplements. Iodine supplements can also discolor the teeth. If you have a hypersensitivity reaction to iodine, you could also experience a metallic taste, burning in the throat or sore teeth or gums. Swelling in the throat can cause asphyxiation, an inability to get air into the lungs and collapse.

Thyroid Changes

Taking iodine supplements over a prolonged period of time can cause hypothyroidism by blocking thyroid hormone production. The risk of thyroid cancers such as thyroid papillary cancer or thyroid follicular cancer may also be higher in people taking iodine supplements. Thyrotoxicosis, a life-threatening complication of having elevated iodine levels, can also occur if you take iodine supplements. Symptoms include fever, confusion, rapid heartbeat and other abnormal irregular heartbeats and congestive heart failure. If you have any of these symptoms while taking iodine supplements, you need immediate medical care.

Stomach Irritation

Iodine can be corrosive to the stomach. An overdose of iodine supplement can cause abdominal pain and sometimes bloody diarrhea. Corrosive gastritis, nausea, vomiting and bleeding from the intestinal tract can also cause overdose.