Calcium and Doxycycline
Supplement–drug interaction evidence from the TruthStack database.
| Severity | HIGH |
|---|---|
| Evidence Tier | Moderate |
| Interaction Type | ABSORPTION INTERFERENCE |
| Mechanism | CHELATION |
| Last Reviewed | 2026-02-15 |
Source Verification
Attestation METHODOLOGY_ATTESTED
Corpus manifest 26b2d684...
Last reviewed 2026-02-15
Live attestation Query API — returns signed DAA ID per request
Data license CC BY 4.0
Summary
Calcium chelates tetracycline antibiotics including doxycycline, reducing absorption by up to 50 percent. Consider separating by at least 2-3 hours. Discuss with your prescriber or pharmacist.
API Reference
GET https://api.truthstack.co/v1/check?c1=calcium&c2=doxycycline
Open, unauthenticated. Returns JSON. Developer documentation
Related Interactions
What this page is and is not. TruthStack is an informational reference database that describes published pharmacological findings. It does not provide medical advice, diagnosis, or treatment recommendations. The information on this page reflects flags in our database and should not replace consultation with a qualified healthcare provider. Always discuss supplement-drug combinations with your prescriber or pharmacist.