Mineral
Magnesium
Magnesium helps turn food into energy and keeps muscles, nerves and bones working normally. It is found in nuts, wholegrains and green vegetables.
What it is
Magnesium is an essential mineral involved in hundreds of processes in the body, most of which is stored in the bones.
What it does
It helps release energy from food, supports normal muscle and nerve function, helps regulate blood pressure, and contributes to healthy bones.
Good sources
Nuts and seeds, wholegrains and wholemeal bread, green leafy vegetables such as spinach, pulses, and dark chocolate.
Deficiency and who is at risk
Deficiency is uncommon from diet alone but can occur with certain conditions, some medicines (such as some diuretics and acid-reducers) or heavy alcohol use. It can cause tiredness, muscle cramps and, if severe, heart rhythm problems.
Balance
Can you have too much?
Too much magnesium from supplements can cause diarrhoea. Getting it from food does not cause this problem.
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
Magnesium: frequently asked questions
Do magnesium supplements help muscle cramps?
Evidence is mixed. Magnesium is important for muscle function, but supplements only clearly help if you are deficient. A balanced diet with nuts, wholegrains and greens usually provides enough.
Can you have too much magnesium?
From food, no. From supplements, high doses can cause diarrhoea and, rarely in people with kidney problems, more serious effects, so stay within recommended amounts.
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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