Iodine is an essential mineral the human body requires to make thyroid hormone, which helps regulate metabolism. Although iodine deficiency in the United States is uncommon, it does occur. Worldwide, about 40 percent of the population is at risk for iodine deficiency, according to the American Thyroid Association. A low-iodine diet may put you at risk for developing certain health conditions.
Background
A low-iodine diet is a diet that contains less than the recommended dietary allowance, or RDA, of iodine. The Institute of Medicine's RDA for iodine is 150 mcg per day for adult men and women, 220 mcg for pregnant women and 290 mcg per day for breastfeeding women. Consistently consuming low levels of iodine can lead to hypothyroidism, a condition that occurs when the body is unable to make enough thyroid hormone to properly regulate metabolism; however, people with hyperthyroidism, a condition where too much thyroid hormone is present in the body, may have to limit dietary iodine consumption.
Sources of Iodine
It's difficult to determine the exact amount of iodine present in foods, as iodine is a nutrient that is not listed on food labels in the United States. Iodized salt is a common source for dietary iodine. Seaweed, fish, dairy products, enriched breads and cereals and iodine-containing multivitamin supplements are also good sources of iodine.
Pregnancy and Lactation
Pregnant and nursing women have increased dietary iodine requirements, and, therefore, have an increased risk for becoming iodine deficient. According to the Office of Dietary Supplements, in the years 2005 to 2008, the median urinary iodine concentrations in pregnant women in the United States were below adequate intake levels. Iodine deficiency during pregnancy and lactation can cause neurodevelopmental deficits, miscarriage, stillbirth, growth retardation or lower IQ levels, according to the Office of Dietary Supplements. For this reason, the American Thyroid Association encourages pregnant and nursing women to take a multivitamin or prenatal vitamin supplement containing at least 150 mcg of iodine each day.
Thyroid Conditions
According to the American Thyroid Association, worldwide iodine deficiency is the most common cause of hypothyroidism, thyroid gland enlargement and goiters. Because the thyroid gland is responsible for using iodine to make thyroid hormone, iodine deficiency can cause a goiter, which is an extremely enlarged thyroid gland. The American Thyroid Association also notes that large goiters can cause choking and difficulty swallowing or breathing.
