Potassium aids in muscle contraction and in maintaining fluid and electrolyte balance in the body. Potassium functions in nerve impulses as well as in carbohydrate and protein metabolism.

While this is not a complete list of examples, some good sources of potassium include:
Vegetables and fruits in general, especially -- potatoes and sweet potatoes -- spinach, swiss chard, broccoli, winter squashes, and parsnips -- dates, bananas, cantaloupes, mangoes, plantains, dried apricots, raisins, prunes, orange juice, and grapefruit juice -- dry beans, peas, lentils.

Milk and yogurt are good sources of potassium and have less sodium than cheese; cheese has much less potassium and usually has added salt.