According to WebMD, iodine is commonly used to prevent iodine deficiency and disinfect wounds. It can also be used to protect against radiation, treat ulcers and purify water.
Iodine is a chemical element found in seawater and some minerals and soils. The body needs iodine but cannot make it. Iodine must be introduced to the body through the diet. Most commercially available iodine is created by processing brine. About 70 to 80 percent of the iodine in the body is located in the thyroid gland. Iodine is necessary for the thyroid gland to make hormones. Lack of iodine creates an enlarged thyroid gland and a swollen neck and results in hypothyroidism. Hypothyroidism is indicated by fatigue, weight gain, dry skin and sensitivity to temperature changes. Iodine deficiency is more common in women than men.
Bernard Courtois discovered iodine in 1811 while trying to extract potassium from seaweed. After extracting the potassium from seaweed, he added sulfuric acid to the remaining liquid. The purple crystals resulting from this procedure helped give this element its name. The Greek word iodes means violet.
Iodine is slightly toxic and can be dangerous in large amounts. Pure iodine is a skin irritant, and the vapor is known to cause eye irritation.