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Mineral

Calcium

Last reviewed September 28, 20261 sources
In short

Calcium is the most abundant mineral in the body and the main structural mineral in bones and teeth. Supplements are mostly calcium carbonate or calcium citrate, which differ in elemental content and how they should be taken.

Research in progress. This ingredient page doesn’t yet meet SuppScout’s bar for a complete reference (sourced evidence summary, considerations and sufficient detail), so search engines are asked not to index it. The information shown is sourced where cited.

Quick facts

Adult RDA
1,000–1,200 mg/day depending on age and sex[1]
Upper limit
2,000–2,500 mg/day depending on age[1]

Common calcium supplement forms

  • Calcium carbonate (~40% elemental; take with food)
  • Calcium citrate (~21% elemental; with or without food)

Detailed form pages for Calcium are being researched.

What researchers have studied it for

Bone health (with vitamin D)

Mixed evidence

Calcium is essential for bone, but supplement trials for fracture prevention have produced mixed results.[1]

Evidence labels summarize the overall body of published research for each topic; they are not a recommendation and do not mean a supplement is appropriate for you. Published research

Typical amounts in supplements

Absorption is highest at doses of 500 mg or less, so larger daily amounts are often split.

[1]

These describe what supplements commonly contain and published reference values — not a recommendation for you.

Food sources

  • Milk, yogurt and cheese
  • Fortified plant milks and juices
  • Canned sardines and salmon with bones
  • Tofu made with calcium sulfate

Potential considerations

  • Calcium can reduce absorption of some antibiotics, levothyroxine and bisphosphonates.
  • Carbonate may cause gas or constipation.

Products containing calcium

No products listed yet

SuppScout hasn’t added calcium products yet.

Sources & references

  1. Calcium: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.govGovernment

SuppScout links to primary and authoritative sources wherever possible. See our editorial policy for how sources are selected and how corrections are handled.

This page is educational and is not medical advice. Talk to a healthcare professional before starting a supplement, especially if you have a medical condition, take medications, or are pregnant or breastfeeding. Medical disclaimer.