Potassium l-aspartate, or simply potassium aspartate, is a safe and bioavailable source of potassium. It is an ionic salt form of potassium combined with l-aspartic acid. Potassium is an essential mineral that prevents muscle cramps by acting as an electrolyte and maintaining fluid levels inside cells. It is also a vasodilator that supports heart health. The most well-known potassium-rich food is the banana, but butternut squash, potatoes, spinach, and broccoli are good dietary potassium sources, too.