Key takeaways
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The NHS says that you should be able to get all the potassium you need by eating a varied and balanced diet. No EU-authorised claim says that potassium stops muscle cramps; the review cited below describes what is known about their cause. The NHS says that taking too much potassium can cause stomach pain, feeling sick and diarrhoea, and that if you take potassium supplements you should not take too much as this could be harmful.
What the potassium claims cover
The exact EU-authorised wording for potassium is shown in the box above.
The muscle cramp question, honestly
A 2009 review (Schwellnus) reported that evidence for the electrolyte depletion and dehydration hypotheses of exercise-associated muscle cramps came mainly from anecdotal clinical observations, case series totalling 18 cases and one small case-control study, that four prospective cohort studies did not support them, and that research data support altered neuromuscular control as the principal mechanism. No EU-authorised claim says that potassium treats or prevents them.
Groups discussed for potassium
- Low fruit and vegetable intake: the NHS lists bananas and some vegetables, such as broccoli, parsnips and brussels sprouts, among the sources of potassium.
- Older people: the NHS says they may be more at risk of harm from potassium because their kidneys may be less able to remove potassium from the blood, and should not take potassium supplements unless advised to by a doctor.
- Medications: ask a doctor or pharmacist before taking a potassium supplement if you take regular medication.
Food sources of potassium
The NHS lists bananas, some vegetables such as broccoli, parsnips and brussels sprouts, beans and pulses, nuts and seeds, fish, beef, chicken and turkey among the good sources of potassium, and says that potassium is found in most types of food.
Potassium supplements and amounts
The NHS says that adults (19 to 64 years) need 3,500mg of potassium a day, that taking 3,700mg or less of potassium supplements a day is unlikely to have obvious harmful effects, and that older people should not take potassium supplements unless advised to by a doctor.
Potassium and electrolytes
See the electrolytes and hydration guide for sports drinks and electrolyte tablets.
Putting it together
The NHS says that you should be able to get all the potassium you need by eating a varied and balanced diet. If cramps are frequent and disruptive, ask a doctor. CapyFuel’s electrolyte price comparisons list products and prices across Malta and Cyprus.
Source: EU Register of nutrition and health claims, NHS – Other vitamins and minerals, Schwellnus 2009 – Cause of exercise associated muscle cramps (PubMed).
Frequently asked questions
Does potassium stop muscle cramps?
No EU-authorised claim says that potassium stops muscle cramps. A 2009 review (Schwellnus) reported that evidence for the electrolyte depletion and dehydration hypotheses of exercise-associated muscle cramps came mainly from anecdotal clinical observations, case series totalling 18 cases and one small case-control study, and that research data support altered neuromuscular control as the principal mechanism.
What does potassium actually do in the body?
The exact EU-authorised wording is shown in the box on this page.
Can you take too much potassium?
The NHS says that taking too much potassium can cause stomach pain, feeling sick and diarrhoea, and that if you take potassium supplements you should not take too much as this could be harmful. It says older people should not take potassium supplements unless advised to by a doctor.
What does the NHS say about potassium supplements?
The NHS says that taking 3,700mg or less of potassium supplements a day is unlikely to have obvious harmful effects, and that you should not take too much as this could be harmful.
What are the best food sources of potassium for athletes?
The NHS lists bananas, some vegetables such as broccoli, parsnips and brussels sprouts, beans and pulses, nuts and seeds, fish, beef, chicken and turkey among the good sources of potassium.