Nutrient glossary

What is calcium?

Calcium is the mineral that builds bone and teeth and keeps muscles, nerves and blood clotting working.

Reviewed 20 July 2026. General information, not medical advice.

The short version

Almost all of your calcium lives in your skeleton, which acts as a bank: when intake is short, the body withdraws from bone to keep blood levels steady. Enough calcium through adulthood, alongside vitamin D and resistance exercise, is how you defend bone density for later life.

Dairy is the dense, well-absorbed source, and tofu set with calcium, tinned sardines with bones, fortified plant milks and leafy greens carry it into any eating pattern.

Daily reference

700 mg a day

The adult reference is 700 mg a day. Absorption depends on vitamin D, so the two are best thought about together.

This is the fixed adult reference used across these pages. In the app, your amount adjusts to your body and way of eating.

Best food sources of calcium

Full ranking
FoodPer servingPer 100g
Almond Milk460 mg184 mg
Tofu (firm)441 mg350 mg
Pizza (cheese)402 mg188 mg
Sardines (canned)351 mg382 mg
Soy Milk310 mg124 mg
Skimmed Milk305 mg122 mg
Mozzarella303 mg505 mg
Milk (semi-skimmed)300 mg120 mg

Common questions

How do I get calcium without dairy?
Calcium-set tofu, fortified plant milks, tinned sardines, kale and almonds together cover the 700 mg reference comfortably.
Do calcium supplements strengthen bones?
Food-first is the evidence-based route. Supplements help when intake is genuinely low, but exceeding needs adds no extra bone.