Potassium is an important mineral that has many functions around the body, including controlling the balance of fluids in the body and possibly helping lower blood pressure.
It is also essential in the functioning of most cell types around the body, in particular, contributing to the contractility of muscles including skeletal muscle, the heart, and the muscles of the digestive system.
Potassium is found in many different foods, but particularly good sources include:
- fruit, particularly bananas
- nuts and seeds
Adults need 3,500mg of potassium a day, and you should be able to get all the potassium you need from your daily diet. If you take potassium supplements, do not take too much because this could be harmful. Taking too much potassium can cause side effects including stomach pain, nausea and diarrhoea.
The Department of Health advises that taking 3,700mg or less of potassium supplements a day is unlikely to cause any harm. However, older people should not take potassium in supplements unless advised to do so by a doctor. This is because people become more at risk of harm from potassium with increasing age, due to an age-related decline in kidney function.