Vitamins & minerals
Calcium
Names you may see: calcium carbonate citrate elemental calcium
The quick take
Calcium supports bones and teeth, muscle contraction and nerve function.
A closer look
What forms will I see on a label?
Calcium carbonate and calcium citrate differ in their use with meals. Compare elemental calcium per serving rather than the compound weight.
Why people use it
People use calcium supplements to help meet needs when food intake is insufficient, often with bone-health goals.
These are common goals and marketing uses. The evidence section below explains what research supports.
What does the evidence tell us?
Adequate calcium supports bone health. Supplement benefits depend on diet and individual circumstances; larger amounts are not automatically better.
What should I know before using it?
Excess intake can cause problems, including constipation and kidney stones in some people. Calcium interacts with certain medicines, so check timing with a pharmacist.
Sources & further reading
NIH Office of Dietary Supplements ↗
Content reviewed: September 30, 2026
General educational information. Follow the product label and seek individual advice when needed.