Calcium: what it does and how much you need
Calcium builds and keeps bones and teeth strong, and helps muscles move, nerves carry messages and blood clot. Adults need 1,000 milligrams a day, or 1,200 for women over 50 and everyone over 70, and the upper limit is 2,500 milligrams a day, or 2,000 over age 50.
General information, not medical advice. Check with a doctor or pharmacist before taking a supplement, especially if you are pregnant or breastfeeding, take any medicine, or are under 18.
In the UK
In the UK, adults need 700 milligrams a day, and the NHS says up to 1,500 milligrams a day from supplements is unlikely to cause harm.
How much you need and the upper limit
| US (NIH) | UK (NHS) | |
|---|---|---|
| Adults need | 1,000 milligrams a day, or 1,200 for women over 50 and everyone over 70 | 700 milligrams a day |
| Upper limit | 2,500 milligrams a day, or 2,000 over age 50 | Up to 1,500 milligrams a day from supplements |
The UK figure is the amount the NHS says is unlikely to cause harm. Figures are for adults.
Food sources
- Milk, yogurt and cheese
- Canned sardines and salmon with bones
- Kale and broccoli
- Fortified plant milks
- Tofu made with calcium
Forms on the label
- Calcium carbonate is best taken with food, while calcium citrate can be taken with or without it.
- Calcium citrate can be taken with or without food, while calcium carbonate is best taken with food.
Dose questions
Quick answers
- What does calcium do?
- Calcium builds and keeps bones and teeth strong, and helps muscles move, nerves carry messages and blood clot.
- How much calcium do adults need?
- Adults need 1,000 milligrams a day, or 1,200 for women over 50 and everyone over 70 (US, NIH). In the UK: 700 milligrams a day (NHS).
- What is the upper limit for calcium?
- US: 2,500 milligrams a day, or 2,000 over age 50. UK (NHS): up to 1,500 milligrams a day from supplements is unlikely to cause harm.
- Which foods have calcium?
- Milk, yogurt and cheese, canned sardines and salmon with bones, kale and broccoli, fortified plant milks, tofu made with calcium.
Sources
- NIH Office of Dietary Supplements fact sheet
https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/ - NHS vitamins and minerals guidance
https://www.nhs.uk/conditions/vitamins-and-minerals/calcium/
Ask Supplement Check yourself
Type a vitamin, mineral or supplement, a dose, or a product name, and get the daily need, the upper limit and any cautions. Open Supplement Check, free, no sign-up.
In Claude or any app that takes MCP connectors, add https://goodturn-mcp.pages.dev/supplementcheck/mcp and ask: “Is 1200 mg of calcium too much?”