Potassium

What it is

Potassium is a mineral found in many foods. It is in fruits, vegetables, beans and dairy. It is also in meat, fish and grains. It is measured in milligrams in many foods.

What it does

It helps nerves send signals in the body. It helps muscles move and relax each day. It helps keep water balance inside body cells. It helps the heart beat in a steady way.

How much people need

• FDA Daily Value for potassium: 4700 mg. It is a reference amount used on Nutrition Facts labels, not a personal target. Source: US FDA.
• WHO: a potassium intake of at least 3510 mg a day (90 mmol) for adults may be beneficial. Source: WHO.

A note on safety

People with kidney disease, and people who take some blood pressure medicines, may need to limit potassium. They should follow the advice of their doctor.

Common myths

• Myth: Bananas are the only good food with potassium. Truth: Many foods have potassium, including beans and potatoes.
• Myth: Fruit is the only place to get potassium. Truth: Vegetables, beans, dairy and grains also have potassium.

Sources and background

The sections on what it is, what it does and the myths are general background from NIH Office of Dietary Supplements: Potassium fact sheet, checked on 29 October 2026. The intake figures above carry their own sources.