Iodine is an essential element that your body uses to make thyroid hormones.  These hormones regulate your metabolism; they influence the rate at which your body either uses energy or stores calories as fat.

Iodine deficiency and the resulting low levels of thyroid hormone can be a cause of infertility in women. It can also lead to autoimmune disease of the thyroid, may increase your risk for thyroid cancer, and other cancers too, such as those of the prostate, breast, endometrium, and ovaries.  Iodine deficiency during pregnancy can harm the mother and the developing infant.

Iodine deficiency used to be common in the United States and Canada but has almost disappeared due to the use of iodized salt, and the addition of iodine to animal feed, which increases the iodine content of animal-based foods, such as cow’s milk.  In countries where foods and substances like salt are not iodine-fortified, iodine deficiency continues to be common.

Symptoms of iodine deficiency include an enlarged thyroid gland (goiter) and hypothyroidism, which causes a variety of symptoms including fatigue, weight gain, weakness and/or depression. Iodine deficiency can also cause the thyroid gland to become overactive.  The overactive state, or hyperthyroidism, is a condition characterized by weight loss, rapid heart beat, and appetite fluctuations.

Consuming too much iodine can be toxic.  Symptoms of toxicity include burning in the mouth, throat and stomach and/or abdominal pain, nausea, vomiting, diarrhea, weak pulse, and coma.  Toxicity typically results from taking too much iodine medicinally as it is very difficult to get too much from food sources.

Health adults need 900 – 1,100 micrograms (mcg) of iodine daily.  Children and teens require smaller amounts, according to age.

The best food sources of iodine include iodized salt, dairy products, eggs and strawberries.

Iodine interacts with many medications, including:

  • Amiodarone
  • Lithium
  • Antithyroid drugs, such as methenamine mandelate (Methimazole), methimazole (Tapazole), potassium iodide (Thyro-Block), and others.
  • ACE inhibitors
  • Angiotensin receptor blockers
  • Potassium-sparing diuretics

Even if you don’t take medication, you should still be cautious about taking iodine as a supplement because of the potential for interactions and adverse effects.  It’s best to consult your MD, ND or pharmacist before doing so.

Foods that are rich in iodine include seafood, sea vegetables, salt, potatoes, dairy foods and strawberries.