Focus On: Iodine

WHAT IT IS: The body uses iodine, a nonmetallic trace element, to create thyroid hormones. The thyroid gland traps iodine from the blood, combines it into thyroid hormones, then stores and releases the hormones into blood circulation as needed by the body. Thyroid hormones help regulate growth, development, metabolism, and reproductive function.


Because iodine is linked to the production and regulation of thyroid hormones, and these hormones are instrumental in the body’s metabolic processes, iodine actually aids in the optimal use of calories and prevents storing calories as excess fat. Iodine also helps remove toxins from the body.

[ Sources ]

Seafood is rich in iodine because marine animals absorb the iodine from seawater, but the iodine content of most foods depends on how much iodine is in the soil where it is grown. Some iodine-rich foods include iodized salt, cod, shrimp, tuna, cow’s milk, boiled eggs, baked potatoes, baked turkey breast, and dried seaweed. Potassium iodide is available as a nutritional supplement and is usually found in multivitamin/multimineral products.

[ Warnings ]

Some studies have linked increased iodine intake to increased incidence of thyroid papillary cancer. Also, those with iodine deficiency, nodular goiter (thyroid enlargement), or autoimmune thyroid disease may be sensitive to iodine intake levels considered safe for the rest of the population.

[ Recommended Dosages ]

The Recommended Dietary Allowance (RDA) of iodine ranges from 110 mcg per day for infants, to 150 mcg per day for adolescents and adults, to 290 mcg per day for women who are pregnant or breast-feeding. For adults, the Tolerable Upper Level Intake (UL) for iodine is 1,100 mcg (or 1.1 mg) per day. (The best source of iodine is from food, and although fortification has been effective in the past, only some salt is now fortified and current culinary trends are limiting the impact of fortification.) The best course of action is to find out what your iodine levels are, then see if your diet provides enough for you or whether supplementation would be recommended.