Sources Of Iodine In A Diet

The human body requires iodine to produce the thyroid hormone, which maintains a normal cell metabolism. The mineral is also necessary for regulating growth and fertility, converting food to energy, and maintaining proper body temperature. A deficiency of this essential nutrient causes a condition known as goiter, or a swelling of the thyroid gland. The recommended daily value of iodine is 150 mcg for adults and teenagers over 14 years of age, according to the EBSCO Health Library. Pregnant women require 220 mcg daily, and breastfeeding mothers need about 290 mcg daily. Because of the use of iodized salt, iodine deficiencies occur only rarely.

Iodized Salt

The primary food source of iodine in the diet is iodized salt, according to the University of Michigan Health System. Table salt contains about 77mcg of iodine per g, or about half of the recommended daily value for adults. Salty processed foods containing large amounts of iodized salt are also a primary source of the mineral in the modern diet. Before iodine was added to table salt, deficiencies were common in inland areas, where salt water from the sea was not readily available.

Seafood and Seaweed

Seafood and seaweed are exceptionally rich in iodine, according to the Linus Pauling Institute at the University of Oregon. Marine animals concentrate the iodine found in sea water, and seaweed absorbs the mineral. Kelp and wakame, two common types of seaweed, contain the highest concentration of iodine. Cod and shrimp provide the largest amounts of the mineral compared to other seafood. One 3-oz. serving of cod, for example, supplies about 99mcg of iodine, and a 3-oz. serving of shrimp provides about 35mcg. The amount of iodine found in seaweed varies, but 1/4 oz. of dried seaweed can contain as much as 4.5mg. Haddock, perch, tuna, sea bass and oysters also contain significant amounts of iodine.

Other Foods

A few beans and vegetables also provide dietary iodine, although in smaller amounts than iodized salt and seafood. According to the University of Maryland Medical Center, plants grown in iodine-rich soil provide a good source of iodine. Navy beans, potatoes, spinach, broccoli, mushrooms and asparagus have been known to supply small amounts of iodine when grown in soil containing the mineral. Other foods that contain iodine include dairy products, such as milk and eggs.