Potassium is a mineral found in most types of food. Good sources of potassium include fruit (such as bananas), vegetables, pulses, nuts and seeds, milk, fish, shellfish, beef, chicken, turkey and bread.

How much do I need?

You should be able to get all the potassium you need from your daily diet. Adults need 3500 mg a day.

What does it do?

Potassium has many important functions. For example it:

  • controls the balance of fluids in the body
  • may also help lower blood pressure

What happens if I take too much?

Taking too much potassium can cause stomach pain, nausea and diarrhoea.

What is our advice?

You should be able to get all the potassium you need by eating a varied and balanced diet. But if you decide to take potassium supplements it's a good idea not to take too much because this could be harmful.

Taking 3700 mg or less of potassium supplements a day is unlikely to cause any harm.

However, older people may be more at risk of harm from potassium. This is because, as we get older, our kidneys may become less able to remove potassium from our blood. Therefore, older people shouldn't have potassium supplements unless on medical advice.