Iodine is an essential component of thyroid hormones and thus vital for thyroid function. Iodine also is needed for the metabolism of cells which converts food into energy.

In countries like the United States and Canada where salt is ionized, iodine deficiency is generally not a problem. However, iodine deficiency is a significant problem in countries without ionized salt. The most common symptom of an iodine deficiency is goiter, enlargement of the thyroid gland. Hypothyroidism, also be caused by an iodine deficiency, can cause fatigue, weight gain, weakness and depression.

Recommended Intake

The Food & Nutrition Board at the Institute of Medicine of the National Academies established recommended dietary allowances for iodine intake. They are listed below in micrograms (mcg) per day.

Sources of Iodine

Natural food sources of iodine include asparagus, garlic, kelp, haddock, bread, eggs, cottage and cheddar cheese, sesame seeds and spinach.