Potassium is a mineral that helps control the balance of fluids in the body, and also helps the heart muscle work properly.
Potassium is found in most types of food.
Good sources of potassium include:
Adults (19 to 64 years) need 3,500mg of potassium a day. You should be able to get all the potassium you need from your daily diet.
Taking too much potassium can cause stomach pain, feeling sick and diarrhoea.
You should be able to get all the potassium you need by eating a varied and balanced diet.
If you take potassium supplements, do not take too much as this could be harmful.
Taking 3,700mg or less of potassium supplements a day is unlikely to have obvious harmful effects.
But older people may be more at risk of harm from potassium because their kidneys may be less able to remove potassium from the blood.
Older people should not take potassium supplements unless advised to by a doctor.