Iodine is a trace mineral that your body needs to synthesize thyroid hormones that are necessary for regulating your body's growth, development, metabolism and body temperature. Most iodine in your body is found in the thyroid gland, but some is also found in the blood and muscles.
Daily Iodine Requirements
1 to 8 years: 90 micrograms per day
9 to 13 years: 120 micrograms per day
14+ years: 150 micrograms per day
Iodine is most commonly found in seafood, iodized salt, and in lesser amounts in dairy products, fruits and vegetables. Iodine can be toxic in large amounts (approximately 1,000 micrograms per day). Ingesting too much iodine can depress thyroid gland function.
Deficiency can result in a thyroid condition called goiter. It was common in the middle regions of the United States in the early 20th century since the soil contained no iodine (plants grown on coastal regions contain small amounts of iodine from the soil).
Other Trace Minerals
Iodine. Northwestern University. Accessed February 17,2010. http://www.feinberg.northwestern.edu/nutrition/factsheets/iodine.html.