Food With Iodide

Iodine is a trace mineral required by your body for the synthesis of thyroid hormones, which are essential for healthy metabolism and energy production. Iodine is found in food as iodide, its anion, which forms compounds with other elements. Most natural foods contain only small amounts of iodide, and it varies depending on soil composition and the use of fertilizers. Some of the richest food sources of iodine are processed foods that contain iodized salt and breads that contain iodated dough. Fish, seafood and sea vegetables are rich natural sources, but highly variable in their iodide content.

IODIZED SALT

In the United States, compounds containing iodide were added to table salt starting in the 1920s in efforts to reduce the incidence of iodine deficiency, which was fairly common at that time, according to “Nutrition and Public Health” by Sari Edelstein. Iodine deficiency initially manifests as a swollen thyroid gland, or goiter, fatigue and reduced metabolism, but can lead to hypothyroidism and its constellation of symptoms. Potassium iodide is the most common compound added to salt, although potassium iodate, sodium iodate and sodium iodide are also used. All of these compounds can supply your body with its required iodine, which is estimated to be 150 micrograms per day for adults. Processed foods tend to contain lots of salt, which isn’t considered healthy, but it is a source of iodine.

SEA VEGETABLES

Sea vegetables are edible plants that grow in coastal regions bordering seas and oceans. A common and recognizable sea vegetable is kelp, which is one of the richest natural sources of iodine. According to the book “Superfoods: The Healthiest Foods on the Planet,” most kelp species contain about 2,500 micrograms of iodide per gram, but some can contain as much as 8,000 micrograms. These high levels could cause problems, as the tolerable upper limit or safety level of iodine is estimated to be 1,100 micrograms daily for adults. Excessive iodine intake can lead to nausea and possibly thyroid gland dysfunction.

SEAFOOD AND FISH

Shellfish, such as shrimp and lobster, and most varieties of saltwater fish can contain high levels of iodide, but the amounts are quite variable and difficult to predict. For example, some species of fish caught in their natural environment may have up to 1,000 micrograms of iodide in a 4-ounce serving, but the same species from a commercial farm may have as little as 70 micrograms in the same portion, according to “DRI, Dietary Reference Intakes: The Essential Guide to Nutrient Requirements.”

DAIRY PRODUCTS

Many dairy products are good sources of iodine, especially yogurt, cow's milk, eggs and mozzarella cheese. According to “American Dietetic Association Complete Food and Nutrition Guide,” 1 cup of low-fat yogurt contains 87 micrograms of iodide, whereas as the same portion of cow’s milk contains 58 micrograms.