Calcium
How much calcium adults need, where to get it without dairy, and why vitamin D is part of the answer.
Last revised
The main mineral in bone and teeth, and essential to muscle contraction, nerve signalling and blood clotting. Bone acts as the body reserve, so sustained shortfall is drawn from the skeleton.
How much adults need
The UK reference nutrient intake is 700mg a day for adults. Higher intakes are advised for some groups, including people being treated for osteoporosis, where around 1,000mg is commonly recommended alongside vitamin D. Adolescents need more than adults, because peak bone mass is being built.
Where to get it
Dairy is the densest common source: a 200ml glass of milk provides roughly 240mg, a small pot of yoghurt around 200mg, and 30g of hard cheese around 220mg. Without dairy: calcium-fortified plant milks and yoghurts, tofu set with calcium sulfate, tinned sardines and pilchards eaten with the bones, kale, pak choi, and fortified breads. Spinach is high in calcium but binds it with oxalate, so very little is absorbed.
Vitamin D is half the story
Calcium absorption depends on vitamin D, which is why the two are discussed and often prescribed together. Meeting a calcium target while deficient in vitamin D achieves less than the number suggests. UK vitamin D advice — 10 micrograms daily in autumn and winter — applies here as elsewhere.
Supplements are not automatically better
Where intake is adequate from food, additional calcium supplementation has not been shown to add benefit and has been associated in some analyses with kidney stones and, more contentiously, cardiovascular risk. Food first is the general advice, with supplements where intake is genuinely low or where a clinician has prescribed them.
At a glance
| Term | Detail |
|---|---|
| UK adult reference intake | 700mg a day |
| Commonly advised in osteoporosis treatment | around 1,000mg with vitamin D |
| 200ml glass of milk | about 240mg |
| 30g hard cheese | about 220mg |
| Small pot of yoghurt | about 200mg |
| Non-dairy sources | fortified plant milks, calcium-set tofu, tinned fish with bones, kale |
| Poorly absorbed source | spinach, because of its oxalate content |
| Required for absorption | vitamin D |
When to get help
See a GP if you have broken a bone from a minor fall, have lost height, or have several osteoporosis risk factors. Speak to your GP before taking calcium supplements if you have had kidney stones, kidney disease, or a parathyroid disorder. Seek advice for symptoms of high blood calcium: persistent thirst, frequent urination, nausea, constipation, bone pain and confusion.
Where to go next
Where this comes from
- NHS - Calcium
- Royal Osteoporosis Society - calcium and bone health
- British Nutrition Foundation - minerals and trace elements
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.