The most common places to find Potassium is in dried fruits, avocado, bananas, winter squash, beans, lentils and beets. It is mostly responsible for retaining proper amounts of water and other fluids in the cells. It also supports normal blood pressure levels and can help the muscles contract. When Potassium levels are low in the body, an abnormal and inconsistent heartbeat may develop. It can also make muscles cramp, twitch, and feel weak. Supplementing potassium can combat this and replenish the body with this essential nutrient.