Potassium

USE: Without this essential mineral, your heart couldn’t beat, your muscles wouldn’t contract, and your brain couldn’t comprehend this sentence. Why? Potassium helps your cells use glucose for energy. It aids the proper functioning of the heart, kidneys, nerves, muscles and digestive system. It is also an electrolyte, a substance that conducts electricity in the body and maintains fluid balance.
SOURCE: Fruits (especially bananas), vegetables (especially avocados) , potatos are a great source, dairy, grains, legumes and meat.