Nature's Bounty Potassium 99 mg Caplets contains Potassium which is an essential mineral that works with sodium to regulate the body's water balance. It also aids in the mineral balance of the blood, supports muscle activity and promotes carbohydrate and protein metabolism. It promotes fluid balance and helps maintain healthy muscle function. It supports natural fluid balance between cells in the body. Potassium is essential for nerve transmissions and the metabolism of carbohydrates and protein.