Last updated: October 2026
Magnesium contributes to the maintenance of normal bones, and about 60% of the body’s magnesium is stored in bone. Studies link higher magnesium intake with slightly higher hip bone density, but a 2016 review found no link with fewer fractures. For bone health, calcium, vitamin D, weight-bearing exercise and not smoking matter most; magnesium is part of a balanced diet.
Below: how magnesium supports bone, what the research shows, how it fits with calcium and vitamin D, how much you need, and what helps prevent osteoporosis.
What magnesium does for bones
Magnesium is part of the bone structure itself, and it’s needed for the parathyroid glands, which control calcium levels, to work normally. It’s also needed to activate vitamin D. Magnesium has an authorised health claim: it contributes to the maintenance of normal bones and teeth.
What the research shows
| Study | What it found |
|---|---|
| Meta-analysis, 2016 (12 observational studies) | Higher magnesium intake was weakly linked with higher bone density at the hip and femoral neck, but not with fewer fractures |
| Review in older adults, 2022 | Higher magnesium intake was linked with higher hip bone density; no link with fractures was found, and long-term supplement trials are needed |
Most evidence is observational, which can’t show cause and effect. Magnesium supplements aren’t a treatment for osteoporosis.
Magnesium, calcium and vitamin D
| Nutrient | Role for bones | UK advice |
|---|---|---|
| Calcium | The main mineral in bone | 700mg a day for adults, mostly from food |
| Vitamin D | Helps absorb calcium | 10 micrograms a day supplement in autumn and winter for everyone. See vitamin D in winter |
| Magnesium | Part of bone; activates vitamin D | 300mg (men) or 270mg (women) a day, mostly from food |
You don’t need to take magnesium at a set ratio to calcium; a varied diet usually provides both. See magnesium vs zinc and magnesium for women.
How much you need
The NHS says adults aged 19 to 64 need 300mg of magnesium a day (men) or 270mg (women), and most people get enough from a varied diet: nuts, seeds, leafy greens, beans and wholegrains. If you take a supplement, 400mg a day or less is unlikely to cause harm. Long-term acid-reducing medicines can lower magnesium levels. See signs of magnesium deficiency and best magnesium supplement UK.
Our Magnesium Glycinate Sleep Complex gives 148mg of magnesium per serving from bisglycinate and citrate, as an evening drink. Magnesium supplements can reduce the absorption of some osteoporosis medicines (bisphosphonates), so take them at different times and ask your pharmacist. We don’t recommend our products during pregnancy or breastfeeding.
What helps prevent osteoporosis
- Regular exercise, including weight-bearing activity such as walking, dancing or resistance training.
- Enough calcium and vitamin D.
- Not smoking, and keeping alcohol to 14 units a week or less.
- Talk to your GP about a bone density check if you’ve had a fracture from a minor fall, have a family history, or take long-term steroids.
FAQs
Is magnesium good for bones?
Magnesium contributes to the maintenance of normal bones. Higher intake is linked with slightly higher hip bone density, but not with fewer fractures.
Should I take magnesium with calcium?
You can, but a varied diet usually provides both. There’s no need to follow a set ratio.
Can magnesium help osteoporosis?
It isn’t a treatment for osteoporosis. Calcium, vitamin D, exercise and prescribed medicines have better evidence.
Can I take magnesium with osteoporosis medicines?
Magnesium can reduce absorption of bisphosphonates, so take them at different times and ask your pharmacist.
Which foods are good for bones?
Dairy or calcium-fortified alternatives, oily fish, leafy greens, nuts, seeds, beans and wholegrains.
Sources
- Farsinejad-Marj M et al. Dietary magnesium intake, bone mineral density and risk of fracture: a systematic review and meta-analysis. Osteoporos Int, 2016.
- Groenendijk I et al. Impact of magnesium on bone health in older adults: a systematic review and meta-analysis. Bone, 2022.
- NHS. Preventing osteoporosis.
- NHS. Vitamins and minerals: magnesium.
