Potassium’s Role in Blood Pressure: Experts Advise Food First, Supplements With Caution

Potassium supplements have the potential to lower blood pressure, but health experts emphasize that most people should focus on consuming potassium-rich foods rather than turning to pills. While potassium plays a beneficial role in managing hypertension due to its effects on blood vessels, excessive intake can be hazardous.

How Potassium Supplementation Influences Blood Pressure  

Dr. Luke J. Laffin, co-director of the Center for Blood Pressure Disorders at Cleveland Clinic, told Verywell that potassium supplements do not significantly affect blood pressure in individuals with normal potassium levels. “However, if your potassium is low, raising potassium, be it with supplements or through potassium-rich foods in one’s diet, can lower blood pressure,” he explained.

Potassium serves several critical functions within the body, including conducting nerve impulses, contracting muscles, and maintaining fluid balance and blood volume — all of which support normal heart function, said Yasi Ansari, MS, RDN, CSSD, a senior dietitian at UCLA Health in Santa Monica. According to Ansari, “Potassium can help lower blood pressure by easing tension in the blood vessel walls and helping reduce extracellular fluid volume.” However, she cautioned that supplements should only be used when necessary, as high potassium intake can be dangerous.

Who Should Consider Potassium Supplements?  

Medical professionals may advise supplementation for individuals who are not getting enough potassium through their diet. Ansari noted that supplements can help correct deficiencies, especially in those who do not consume enough potassium-rich foods or who lose significant amounts through diuretic use, intense physical activity, diarrhea, or vomiting. Additional groups that may benefit include people experiencing malnutrition or those undergoing dialysis.

However, potassium supplements are rarely recommended solely for managing high blood pressure. “For most people, boosting potassium through food is the safest and most effective approach,” Ansari stated. In certain cases, such as individuals taking medications that cause hypokalemia (low potassium), supplements may be prescribed under close medical supervision.

The Risks of Potassium Supplementation  

Taking potassium supplements without medical guidance can lead to serious health consequences. Dr. Laffin warned that excessive potassium, also known as hyperkalemia, can result in life-threatening heart arrhythmias. The risk is even greater in patients with kidney disease, as the kidneys are responsible for excreting excess potassium. “If a patient has kidney disease, they are at higher risk of hyperkalemia and need to be more careful about potassium supplements and medications that raise potassium levels,” Laffin advised.

Best Ways to Increase Potassium Intake  

Experts agree that prioritizing potassium-rich foods is the preferred method for increasing potassium levels. Many foods naturally contain potassium and can help lower blood pressure without the need for supplements. Ansari suggested selecting foods that provide approximately 20% of the daily value (DV) for potassium, which amounts to 4,700 milligrams per day.

In summary, potassium can play a valuable role in blood pressure management, but experts caution against unsupervised use of supplements. A diet rich in fruits and vegetables remains the safest and most effective way to boost potassium and support heart health.