Potassium Iodide (KI) is a compound that contains Iodine, a nutrient necessary for normal thyroid function. Iodine in the form of Iodide is an integral part of thyroid hormones, which regulate cellular metabolism and energy production. NOW Potassium plus Iodine also supplies 99 mg of Potassium and 5 mg of sodium per tablet. These minerals impact water balance in the body. Our NOW natural and organic Supplements are an effective way to ensure you and your loved ones are getting essential vitamins, minerals and nutrients for daily optimal health. Since 1968, NOW has been making top quality products that are tested to the highest standards to empower people to lead healthier lives. Our promise - what is on the label, is precisely what is in the bottle.