Mineral
Potassium
Potassium helps control fluid balance, blood pressure and normal muscle and heart function. It is found in fruit, vegetables, pulses and fish.
What it is
Potassium is an essential mineral and electrolyte that works alongside sodium to control fluid balance and nerve and muscle signals.
What it does
It helps control the balance of fluids in the body, supports normal blood pressure, and is needed for muscles and the heart to work properly.
Good sources
Fruit such as bananas and oranges, vegetables, potatoes, pulses, nuts, fish and milk.
Deficiency and who is at risk
Low potassium can result from severe vomiting or diarrhoea, some medicines (such as certain diuretics), or kidney problems, causing weakness, cramps and, if severe, heart rhythm problems.
Balance
Can you have too much?
Very high potassium is dangerous for the heart and is a particular risk in people with kidney disease or on certain medicines, who may be advised to limit high-potassium foods. Do not take potassium supplements without medical advice.
Education and reference only. This is general nutrition information, not personal advice, and does not give doses. Ask a pharmacist, GP or registered dietitian before starting supplements, especially with a health condition or in pregnancy.
Answers
Potassium: frequently asked questions
Is potassium good for blood pressure?
Yes, a diet rich in potassium (from fruit and vegetables) can help lower blood pressure, partly by balancing the effects of salt. However, people with kidney problems may need to limit it.
Who needs to be careful with potassium?
People with kidney disease or on certain heart and blood pressure medicines can be at risk of dangerously high potassium and may be advised to limit high-potassium foods and avoid supplements.
Related
More on minerals and nutrition
Sources
Where this is drawn from
- NHS — Vitamins and minerals
- British Dietetic Association (BDA)
- UK Scientific Advisory Committee on Nutrition (SACN)
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