Skip to main content

antacids and calcium

Antacids reduce calcium absorption

What's happening

Proton pump inhibitors (omeprazole, pantoprazole) and H2 blockers reduce stomach acid needed for calcium absorption. Long-term PPI use linked to increased fracture risk. Calcium citrate absorbs better than carbonate in low-acid environment.

Recommendation

Take calcium separately from antacids. Use calcium citrate if on long-term PPIs.

Timing

Take calcium 2 hours before or after antacids

Sources

  • — JAMA
  • — PMID: 17190895
  • — Osteoporosis International

Frequently Asked Questions

Can I take antacids and calcium together?

Antacids reduce calcium absorption. Take calcium separately from antacids. Use calcium citrate if on long-term PPIs.

How should I time antacids and calcium?

Take calcium 2 hours before or after antacids

Is this interaction dangerous?

This interaction is rated “Info” by Formulate. Proton pump inhibitors (omeprazole, pantoprazole) and H2 blockers reduce stomach acid needed for calcium absorption. Long-term PPI use linked to increased fracture risk. Calcium citrate absorbs better than carbonate in low-acid environment.

Want to check your whole stack?

The free checker lets you add any combination of supplements and medications at once. Formulate's desktop app goes further — every stack change surfaces interaction alerts automatically.

Open the checkerGet the desktop app

Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.