Calcium Hydroxyapatite

Premium whole-bone calcium complex identical to human bone mineral, providing calcium plus cofactors for superior bone health support

Scientific nameCalcium Hydroxyapatite FormulaCa10(PO4)6(OH)2 Molecular weight1004.6 g/mol CAS12167-74-7

40 absorption score

9 safety / 10

60 USD per month

39 elemental calcium %

6 documented interactions

Check it against something

Evidence level A

Calcium Hydroxyapatite with:

88 out of 100

Needs attention Separate by 2-4 hours to avoid the interaction below.

Check it against your whole stack →

What it does

mechanism and evidence for each claim

Superior bone-building complex

Provides calcium in same form found in human bones

Bio-identical hydroxyapatite structure matches bone mineral Evidence B-grade 3-6 months

Enhanced absorption and utilization

Better absorbed and utilized than simple calcium salts

Whole bone matrix provides cofactors that enhance calcium utilization Evidence B-grade 4-8 weeks

Complete bone matrix support

Provides phosphorus, collagen, and trace minerals

Whole bone extract contains all components needed for bone formation Evidence A-grade 2-4 months

Optimal calcium-phosphorus ratio

Natural 2:1 calcium to phosphorus ratio for bone health

Mimics natural bone mineral composition for optimal utilization Evidence A-grade 6-12 months

Stomach acid independent

Well absorbed regardless of stomach acid levels

Pre-digested bone matrix doesn't require acid for dissolution Evidence B-grade Immediate absorption benefit

Others take these for the same thing

Same goal, different mechanism — check any of them against this one

Calcium Bone health & muscle function 1,000-1,200 mg A 30% Turmeric Anti-inflammatory & antioxidant 300-1000mg A 3% Vitamin D3 Bone health & immune support 1000-2000 IU A 85% Collagen Peptides Skin health & joint support 5-15g B 85% Calcium Carbonate Affordable bone health & antacid 1000-1200 mg A 25% Phosphorus Bone health & energy metabolism 700-1250mg A 80%

Or a different form of the same thing

the comparison people search most

Calcium Hydroxyapatite vs Calcium absorption 40 against 30 · $60 against $20 a month 30% Calcium Hydroxyapatite vs Calcium Carbonate absorption 40 against 25 · $60 against $10 a month 25% Calcium Hydroxyapatite vs Calcium Citrate absorption 40 against 45 · $60 against $20 a month 45%

All Calcium forms ranked by absorption →

Every pair we checked

12 combinations scored by the engine

Calcium Hydroxyapatite + Whey Protein Very high calcium may interfere with protein absorption Needs attention 61

Calcium Hydroxyapatite + Caffeine No documented interaction either way No known interaction 70

Calcium Hydroxyapatite + Creatine Monohydrate No documented interaction either way No known interaction 70

Calcium Hydroxyapatite + Calcium Carbonate No documented interaction either way No known interaction 70

Calcium Hydroxyapatite + Bovine Collagen No documented interaction either way No known interaction 70

Calcium Hydroxyapatite + DHA No documented interaction either way No known interaction 70

Calcium Hydroxyapatite + Turmeric No documented interaction either way No known interaction 70

Calcium Hydroxyapatite + Magnesium Oxide High calcium can interfere with magnesium absorption Needs attention 76

Calcium Hydroxyapatite + Lactase Enhanced calcium absorption from dairy sources Works better together 82

Calcium Hydroxyapatite + Vitamin D3 Reduces vitamin D conversion efficiency Needs attention 88

Calcium Hydroxyapatite + Vitamin C (Ascorbic Acid) Essential for calcium absorption and bone formation Works better together 99

Calcium Hydroxyapatite + Vitamin B12 (Methylcobalamin) Essential for calcium absorption and bone formation Works better together 99

Dosage

With or without food

Daily800-1200 mg

Maintenance600-800 mg daily

Therapeutic1000-1500 mg daily

Bone building800-1200 mg daily (divided)

Elemental calciumContains ~24% elemental calcium

Upper limit 2500 mg NIH ODS

Before you take it

VeganYes

When to expect it

First Effects2-4 weeks for improved calcium status

Peak Benefits6-18 months for optimal bone density improvements

Deficiency DevelopmentMonths to years with inadequate intake

Toxicity OnsetVery rare, excellent safety profile

How to measure it

$200-400 for DEXA scan

MarkerBone turnover markers (CTX, P1NP), DEXA scan

OptimalNormal bone density T-score > -1.0

Deficient belowOsteopenia T-score -1.0 to -2.5

FrequencyEvery 1-2 years for bone density monitoring

Bone density scans more relevant than blood calcium

What people actually reported to the FDA

CAERS, 569 reports naming it as the suspect

Most reported effects

Dyspnoea 58

Vomiting 33

Excluded from the list above: choking (207), dysphagia (71), foreign body trauma (54), foreign body (33). Those are people struggling with the tablet itself, not with the compound.

Named as the suspect 569 reports of 1,000+ that mention it at all

Serious outcome 89% hospitalisation, emergency room or worse

Other Serious or Important Medical Event468

Hospitalization82

Visited a Health Care Provider63

Reports are voluntary and unverified — they record what someone experienced while taking something, not what the compound caused. Counts skew towards products people take a lot of, and a serious outcome is more likely to be reported than a mild one, so these are not rates. How we filter them →

What actually reaches you

The label counts the carrier, your body does not

Elemental calcium 39.9% of 1004.6 g/mol

Absorption Moderate 40 of 100 · middle of the range for this compound

Delivered daily 159.6 mg

Cost per 100 mg delivered $1.25 comparative — uses the absorption score, not a measured percentage

A 500 mg capsule of Calcium Hydroxyapatite contains 200 mg of calcium. How much of that crosses into your blood is not measured for this form — the absorption score ranks it against other forms, it is not a share of the dose. How this is calculated →

Works better with

4 documented

Vitamin D

Essential for calcium absorption and bone formation

Vitamin D regulates calcium metabolism and bone mineralization · level A

Vitamin K2

Directs calcium to bones and away from soft tissues

K2 activates osteocalcin and matrix Gla protein · level A

Magnesium

Essential cofactor for bone formation and calcium metabolism

Required for bone mineralization enzymes · level A

Vitamin C

Essential for collagen synthesis in bone matrix

Cofactor for collagen cross-linking enzymes · level A

What not to take with Calcium Hydroxyapatite

2 documented

Excessive Phosphorus

Very high phosphorus intake may affect calcium balance

Disrupted calcium-phosphorus homeostasis · mild significance

Aluminum

Aluminum may interfere with bone formation

Competitive interference with calcium utilization · mild significance

Medication interactions

Discuss these with a pharmacist before combining

tetracycline-quinolone-antibiotics Moderate

Calcium may reduce antibiotic absorption

What to do: Space doses 2 hours apart

levothyroxine Moderate

May reduce thyroid hormone absorption

What to do: Take thyroid medication 4 hours before calcium

bisphosphonates Moderate

May reduce bisphosphonate absorption

What to do: Take bisphosphonate 2+ hours before calcium

Available forms

bioavailability compared

Ranks 2 of 4 among calcium forms. Calcium Citrate absorbs better — 45%. Compare all forms →

Microcrystalline Hydroxyapatite Complex (MCHA) 40

Microcrystalline Hydroxyapatite Complex (MCHA): Bio-identical structure, Complete bone matrix, Acid-independent, Superior utilization

Food sources

before you supplement

Hydroxyapatite not found in foods Only available as processed supplement · 40

Bone broth Contains some bone minerals · 25

Small fish with bones Natural bone mineral content · 30

Too little

deficiency signs

Progressive bone loss and low bone density
Increased fracture risk and bone fragility
Poor bone healing and recovery
Dental problems and tooth loss
Height loss due to spinal compression
Chronic bone and joint pain
Postural changes and kyphosis

Too much

toxicity signs

Excellent safety profile:
Rare hypercalcemia with excessive intake
Possible kidney stone formation with very high doses
Generally very well tolerated
No serious adverse effects reported

Who benefits most

osteoporosis-prevention-treatment

Superior form for serious bone health concerns

800-1200 mg daily (divided doses)

postmenopausal-women-premium

Best calcium form for those wanting optimal bone support

1000 mg daily with vitamin D and K2

low-stomach-acid-elderly

Excellent absorption regardless of gastric acid levels

600-1000 mg daily

athletes-bone-stress

Complete bone support for high-impact activities

800-1200 mg daily

comprehensive-bone-health

Premium choice for complete bone matrix support

600-1000 mg daily

Where to buy it

compare forms first

Look for Calcium Hydroxyapatite at 800-1200 mg per serving. The form that matters here is Microcrystalline Hydroxyapatite Complex (MCHA).

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What else affects it

Beyond other supplements

Excessive phosphorus

Very high phosphorus intake may affect calcium balance

Disrupted calcium-phosphorus homeostasis

Aluminum

Aluminum may interfere with bone formation

Competitive interference with calcium utilization

How it works

Bio-identical hydroxyapatite structure matches human bone mineral
Whole bone matrix provides calcium, phosphorus, and cofactors
Type I collagen component supports bone matrix formation
Natural growth factors may enhance bone formation
Optimal calcium-phosphorus ratio supports bone mineralization
Trace minerals provide additional bone health support

Key findings

what the evidence supports

Superior to calcium carbonate for bone density in clinical studies
Better absorbed and utilized than simple calcium salts
Effective for osteoporosis prevention and treatment
Well-tolerated with minimal side effects

Sources: NIH Examine.com · data reviewed 2026-08-02

Compiled by Denis, who maintains this database and holds no medical qualification — every figure here is sourced or derived, never asserted. How we calculate it →

Common questions

What are the benefits of Calcium Hydroxyapatite?

Documented effects: Superior bone-building complex; Enhanced absorption and utilization; Complete bone matrix support; Optimal calcium-phosphorus ratio. Provides calcium in same form found in human bones

How much Calcium Hydroxyapatite should you take per day?

The common daily range is 800-1200 mg. By goal — maintenance: 600-800 mg daily; therapeutic: 1000-1500 mg daily; bone building: 800-1200 mg daily (divided); elemental calcium: Contains ~24% elemental calcium.

When is the best time to take Calcium Hydroxyapatite?

With or without food. First effects are typically reported within 2-4 weeks for improved calcium status.

What are the side effects of Calcium Hydroxyapatite?

At excessive doses: Excellent safety profile:, Rare hypercalcemia with excessive intake, Possible kidney stone formation with very high doses, Generally very well tolerated, No serious adverse effects reported. Safety rating at normal doses is 9 out of 10.

What should you not take with Calcium Hydroxyapatite?

Separate it from Excessive Phosphorus, Aluminum by two to four hours. Very high phosphorus intake may affect calcium balance

Does Calcium Hydroxyapatite interact with medications?

Documented interactions with tetracycline-quinolone-antibiotics, levothyroxine, bisphosphonates. Discuss these with a pharmacist before combining.

How much Calcium Hydroxyapatite is too much?

The tolerable upper intake level is 2500 mg per day for adults, per NIH ODS. Above that, the risk of adverse effects rises: Excellent safety profile:, Rare hypercalcemia with excessive intake, Possible kidney stone formation with very high doses.

How do you know if you need Calcium Hydroxyapatite?

The marker is Bone turnover markers (CTX, P1NP), DEXA scan, optimal range Normal bone density T-score > -1.0. Common deficiency signs: Progressive bone loss and low bone density, Increased fracture risk and bone fragility, Poor bone healing and recovery, Dental problems and tooth loss.

Taken for

38 Joints & Bones

Vitamin D3 · Calcium Carbonate · Bovine Collagen