Putting potassium in perspective

Too much or too little potassium can harm the heart. Diet, medications, and kidney function can affect the body’s potassium level. Dietary potassium helps keep blood pressure in a normal range, but most Americans don’t consume enough of this mineral. However, people taking medications that raise potassium levels—which includes certain drugs to treat high blood pressure and heart failure—should avoid salt substitutes made with potassium chloride.