Most adults need about 3,500-5,000 milligrams of potassium per day to help lower or manage blood pressure. Potassium works best when it comes from food, especially for people with high blood pressure or high sodium intake.
Potassium is found in many everyday foods, making it easy to meet your needs through your diet. Fruits and vegetables are some of the best sources. This includes:
- Tomatoes: 523 milligrams (mg) in 1 cup of a ripe, cooked red tomato
- Potatoes: 413 mg in 100 grams of a raw potato with the skin on
- Squash: 406 mg in 1 cup of cubed raw winter squash
- Bananas: 375 mg in a ripe or slightly ripe banana
- Prunes: 347.5 mg in five prunes
- Apricots: 323 mg in a typical serving of 140 grams
- Oranges: 232 mg in an average-sized orange
- Spinach: 287 mg in a half cup of cooked spinach
Beans and lentils are also high in potassium, as are dairy foods like milk and yogurt. Fish, poultry, and meats provide potassium too, along with nuts and seeds.
Whole-grain foods like brown rice and whole-wheat bread contain more potassium than refined versions. These foods also provide fiber and other nutrients that support heart health.
Potassium supplements may help lower blood pressure for some people, but they aren’t the first choice for most adults. It’s preferred that potassium comes from food. Still, a healthcare provider may suggest a low- to moderate-dose potassium supplement if dietary intake isn’t enough.
Some studies suggest potassium supplements can lower blood pressure, particularly in people with high blood pressure. But results are mixed, and supplements don’t always provide the same benefits as potassium from food.
Potassium can lower blood pressure mainly by helping the body get rid of excess sodium. Sodium causes the body to hold on to water, which raises blood pressure. Potassium works in the opposite way. It signals the kidneys to release more sodium into the urine. When more sodium leaves the body, extra fluid follows, which helps lower blood pressure.
This effect is especially important for people who eat foods high in sodium or are “salt sensitive,” meaning their blood pressure rises easily with sodium intake. Higher potassium intake can help balance fluid levels in the blood and supports normal kidney function. Research shows that when potassium intake is higher, the kidneys reduce sodium reabsorption more effectively, even if sodium intake is high.
Potassium also relaxed blood vessels, which lowers blood pressure.
Too much potassium can be dangerous for some people. High potassium levels in the blood is called hyperkalemia. This happens when the body can’t remove excess potassium, most often due to kidney disease. Healthy kidneys filter extra potassium into the urine, but damaged kidneys may allow potassium to build up in the bloodstream.
People with kidney disease, those on dialysis, or people taking blood pressure medications should talk with a healthcare provider before increasing potassium intake or using salt substitutes that contain potassium.
- Take note of how much potassium you’re getting in your diet.
- Talk with your healthcare provider about your potassium needs and the safest ways to boost your intake.
- Monitor for signs and symptoms of too much potassium—which could include muscle weakness, nausea, unusual heartbeats, and chest pain—and contact your healthcare provider right away if you notice any symptoms.
