POTASSIUM: 

WHAT DOES POTASSIUM DO?
The mineral potassium is an electrolyte: It’s one of the major nutrients involved in maintaining the proper electrical charge in the body. It’s the flow of potassium and sodium, in and out of cells, that maintains the normal functioning of the heart, brain, kidney and skeletal muscles. Without potassium it would be impossible for your body to maintain a regular heartbeat or properly transmit nerve signals to muscles so they can contract. A high-potassium diet also offsets some of the harmful effects of too much salt (sodium) on blood pressure, and it seems to be protective against deaths from two big killers, high blood pressure and stroke. Potassium is also vital for maintaining the balance of water in the body.

HOW MUCH POTASSIUM DO YOU NEED?
There’s no recommended daily allowance (RDA) for potassium. To keep blood pressure in check, reduce the risk of kidney stones and reduce bone loss, aim for 4.7 grams (4,700 milligrams) daily of potassium through food, and 5.1 grams if you’re breastfeeding.

You lose potassium when you sweat. And if you’re vomiting and dealing with diarrhea, beware; both can cause rapid loss of the nutrient. Potassium depletion can lead to fatigue, overall weakness, confusion and muscle pains or cramps. If your urine is dark yellow you have lost too much fluid and electrolytes; replenishing with water is often sufficient, but if you’re especially depleted from exercise or illness you can also try an electrolyte drink (we suggest opting for varieties sold in health food stores, which have fewer chemicals than mainstream brands).

Certain medications such as diuretics, cortisone drugs or digitalis can also cause you to lose potassium, so your doctor may suggest that you take supplements alongside your prescription.

Supplements can produce gastrointestinal discomfort and a buildup of toxic levels of potassium in the blood, which can cause irregular heartbeats, so it’s best to only take them with a doctor’s OK.

WHERE CAN YOU GET POTASSIUM?
Bananas are famous for containing lots of potassium, but many fruits and vegetables—especially leafy greens, vine fruits (like tomatoes, cucumbers and zucchini), root vegetables and citrus fruits—as well as dairy, are excellent sources. A balance of potassium, sodium (and calcium) are essential for healthy blood pressure control. That’s why we’ve included both potassium and sodium numbers for some of our favorite foods:

You can look up the calcium and potassium content of other foods using the USDA National Nutrient Database for Standard Reference.