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Types of Calcium: Forms & Bioavailability

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Forms Comparison

FormBioavailabilityBest ForElemental Content
Calcium CitrateHighGeneral supplementation — absorbs well with or without food; best for those on acid-reducing medications21% elemental calcium by weight
Calcium CarbonateModerateBudget option — highest elemental calcium per pill, but requires stomach acid for absorption40% elemental calcium by weight
Microcrystalline Hydroxyapatite (MCHC)Moderate-HighBone health — contains calcium in its natural bone matrix with collagen and growth factors24% elemental calcium by weight
Calcium MalateHighWell-tolerated option with good solubility13% elemental calcium by weight

Calcium Citrate

Bioavailability: High. Best for: General supplementation — absorbs well with or without food; best for those on acid-reducing medications. Elemental content: 21% elemental calcium by weight.

Calcium Carbonate

Bioavailability: Moderate. Best for: Budget option — highest elemental calcium per pill, but requires stomach acid for absorption. Elemental content: 40% elemental calcium by weight.

Microcrystalline Hydroxyapatite (MCHC)

Bioavailability: Moderate-High. Best for: Bone health — contains calcium in its natural bone matrix with collagen and growth factors. Elemental content: 24% elemental calcium by weight.

Calcium Malate

Bioavailability: High. Best for: Well-tolerated option with good solubility. Elemental content: 13% elemental calcium by weight.

Full Calcium Guide

References

  1. (). Calcium plus vitamin D supplementation and the risk of fractures. New England Journal of Medicine. DOI
  2. (). Calcium intake and risk of fracture: systematic review. BMJ. DOI
  3. (). Calcium intake and bone mineral density: systematic review and meta-analysis. BMJ. DOI