Potassium is a “macromineral,” along with calcium, chloride, magnesium, phosphate and sodium, according to The Merck Manuals Online Medical Library. Macrominerals serve as electrolytes, conducting electrical impulses in the body, and are required for bone, muscle, heart and brain function, and to maintain acid-base balance. A healthy diet that includes a variety of fruits and vegetables can supply your daily requirement of potassium, which is 4,700 milligrams per day as reported by the Linus Pauling Institute.
The National Institutes of Health advises good fruit sources of potassium include all citrus fruits, bananas, cantaloupe, figs, raspberries, strawberries, plums, kiwi, grapes, apricots, tomatoes and nuts. One medium banana contains 422 milligrams of potassium; a 1/2-cup serving of prunes contains 637 milligrams and a 1-ounce serving of almonds contains 200 milligrams of potassium.
Many vegetables are good sources of potassium, including green leafy vegetables such as broccoli, Swiss chard, mustard greens, turnip greens, collard greens, kale, romaine and spinach. Beans, such as lima, pinto, kidney, lentils and green beans, are good sources. Potatoes and cucumbers are also good, especially when you eat their skins. A medium baked potato, with skin, contains 926 milligrams of potassium; a 1/2-cup serving of lima beans contains 485 milligrams and a 1/2-cup serving of spinach has 420 milligrams. Other good vegetable sources are celery, peas, brussel sprouts, beets, asparagus, bell peppers, cauliflower, cabbage, sweet potatoes, winter and summer squashes, and eggplant.
Having too much potassium is called hyperkalemia; having too little is called hypokalemia. Potassium balance is affected by the amounts of sodium and magnesium in your blood. According to the University of Maryland Medical Center, a diet high in salt can increase the need for potassium. Potassium is available in supplements and is often a component of multivitamins. However, it is best to talk to your doctor before taking any supplements since too much potassium is as dangerous as too little.