What is potassium?

Potassium is an essential mineral that every cell of the body needs. It is the most common positive ion inside cells, and an adult who weighs 175 pounds (79 kg) holds about 140 g of it.^[1] Fruit, vegetables, beans, potatoes, milk, meat, fish and nuts all contain potassium.^[1] Supplements use potassium chloride, citrate, phosphate, aspartate, bicarbonate or gluconate.^[1] Many salt substitutes replace part or all of the sodium chloride in salt with potassium chloride.^[1] Potassium iodide, found in some supplements, is a source of iodine, not of potassium.^[1]