Iodide

is the ion form of Iodine. It occurs when iodine bonds with potassium. It is commonly used as a medication and dietary supplement, due to its role in thyroid function and the production of thyroid hormones, which are vital regulators of metabolic rate and of physical and mental development. It also contributes to the function of the immune system, energy production, normal cognitive and neurological function, and the maintenance of skin.