What Does Iodine Help To Control?

Iodine is a trace mineral that is essential for your health. Even though you require only small amounts of iodine to meet your physiologic needs, it isn't always easy to obtain enough iodine from dietary sources. In fact, the World Health Organization reports that iodine deficiency is the world's most common preventable cause of brain damage. Iodine's most important role in your body is in the formation of thyroid hormones, which ultimately control metabolism, reproduction and growth and development. Ask your physician if you need iodine supplementation.

Thyroid Hormones

Your thyroid gland is specifically designed to trap and concentrate iodine from your bloodstream. In his book, "Staying Healthy with Nutrition," Dr. Elson Haas states that your thyroid contains 20 percent of your total iodine stores, making iodine concentrations in this small organ 1,000 times higher than other tissues. Your thyroid uses iodine to produce two important hormones: triiodothyronine, or T3, and thyroxine, or T4. T3 and T4 act on receptors in your cells to control protein synthesis, hormone production, enzyme activity and a variety of other metabolic functions.

Hypothyroidism

Insufficient dietary iodine deprives your thyroid of its ability to produce and secrete T3 and T4. To trap what iodine is available during times of deficiency, your thyroid enlarges, leading to a condition called goiter. Continued deficiency leads to overt hypothyroidism, which is characterized by fatigue, poor mental function, reproductive impairment, cold intolerance, weight gain, fluid retention, hair loss and congestive heart failure. According to an October 1998 editorial in "The Journal of Clinical Endocrinology and Metabolism," hypothyroidism occurring during fetal development or early childhood can result in irreversible mental retardation.

Other Uses

Iodine supplementation is usually only useful in situations where iodine deficiency already exists. For example, taking additional iodine to promote hair growth is not going be helpful unless your hair loss was originally due to iodine deficiency. Iodine deficiency might also contribute to fibrocystic breast changes, according to "Staying Healthy with Nutrition: Iodine;" supplementation is useful for some women with this condition. Supplemental iodine helps prevent your thyroid from absorbing radioactive iodine following nuclear accidents or other radiation exposures, while topically applied iodine solutions are useful antibacterial agents.

Considerations

Most Americans acquire sufficient iodine from iodized table salt, which contains around 75 micrograms per gram of salt. Iodized salt is also added to many processed foods. If you choose to avoid iodized salt, you may have to make a special effort to obtain enough iodine from your diet. Seafood, shellfish and marine vegetables are excellent iodine sources, while plants grown on iodine-rich soils contain reasonable amounts. However, many soils are depleted of iodine, so fruits and vegetables are not always a reliable means of obtaining this important nutrient.

Requirements and Warning

The recommended daily intake of iodine varies from 110 micrograms for infants to 290 micrograms for nursing mothers. Most people tolerate larger amounts without apparent problems, but excessive iodine consumption has been linked to autoimmune thyroid conditions, such as Grave's disease, and some forms of thyroid cancer, as noted in the October 1998 issue of "The Journal of Clinical Endocrinology and Metabolism." Furthermore, high iodine intake can actually inhibit thyroxine production if your thyroid is already functioning normally. Although iodine is an essential nutrient, you can develop allergies to some iodine-containing products. Consult your doctor before taking extra iodine.