Potassium is the main positively charged ion found inside cells. It is actively pumped inside cells by millions of sodium-potassium pumps so that its concentration inside cells is 30 times greater than in the surrounding, extracellular fluid. This generates a small, negative, electrical charge across the cell membrane which is essential for life.
The flow of potassium in and out of cells allows muscles to contract, the heart to beat, nerves to conduct messages, and regulates the production of energy.
Because high or low potassium levels can affect vital functions, its concentration within the blood is tightly controlled within a narrow range.
Most people do not need potassium supplements.
