Ask the doctor: Does potassium lower blood pressure?

Q. I've heard that extra potassium can improve my blood pressure. What do you think?

A. It can in most people. Potassium is a mineral that is essential to health. But, like a lot of essential minerals and vitamins, the question is: how much do we need? Answering that begins with two other questions. First, how much potassium is in your daily diet? (You'd work with a dietitian to answer that one.) Most people in the United States do not eat enough potassium-rich foods, according to the National Health and Nutrition Examination Survey.