Iodine Supplements May Be Too Much of a Good Thing
Avoid excessively high doses, thyroid experts warn
Wednesday, June 12, 2013
Adequate iodine intake is required for normal function of the thyroid, a gland in the neck that produces hormones that control the rate of many bodily activities. But too much iodine can lead to thyroid dysfunction.
Daily supplements containing more than 500 micrograms of iodine should be avoided, the association recommended. Many iodine, potassium iodide and kelp supplements contain iodine amounts that are up to several thousand times higher than the daily tolerable upper limit of 1,100 micrograms per day, they noted.
The recommended daily limit for iodine intake is 150 micrograms for men and non-pregnant women. The recommended daily intake is 220 to 250 micrograms for pregnant women and 250 to 290 micrograms for women who are breast-feeding.
Women should take multivitamins containing 150 micrograms of iodine daily before conceiving, during pregnancy and while breast-feeding, the experts said in an association news release.
"For other individuals, the U.S. diet generally contains enough iodine to meet nutritional needs, with common sources being iodized salt, dairy products, breads and seafood," Dr. Angela Leung, chair of the association's public health committee and an assistant professor of medicine at Boston University School of Medicine, said in the release.
There are only a few medical conditions in which the short-term use of high amounts of iodine is indicated, the association added.