Iodine is a non-metallic element that is a member of the halogen group. It was discovered in 1811 and named after the Greek word for violet due to the color of its vapor. Iodine is used as a disinfectant, in pharmaceuticals, food supplements, and to prevent iodine deficiency. High exposure can cause toxicity symptoms like skin and lung irritation. Iodine deficiency can lead to myxedema while excess intake of certain foods can inhibit iodine absorption and cause goiter.