Interaction guide

Calcium and iron

Calcium can reduce non-heme iron absorption when they share the same meal or supplement window.

Default spacing rule

Use a cleaner iron slot away from calcium-heavy meals, calcium supplements, and mineral multis unless a clinician gives a different plan.

Interaction map

Calcium and iron: the decision path

Check these

Iron supplementsCalcium supplementsCalcium-heavy mealsMineral multis

Default action

Use a cleaner iron slot away from calcium-heavy meals, calcium supplements, and mineral multis unless a clinician gives a different plan.

Why it matters

Lower iron absorptionMore confusing ferritin follow-upUnnecessary dose escalation when timing is the issue

Products to check

  • Iron supplements
  • Calcium supplements
  • Calcium-heavy meals
  • Mineral multis

Why it matters

  • Lower iron absorption
  • More confusing ferritin follow-up
  • Unnecessary dose escalation when timing is the issue

Sources and related pages

Hallberg et al. calcium and iron absorptionNIH ODS iron fact sheetCalcium and iron timing guideIron monographStack timing planner

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These statements have not been evaluated by the FDA. Not intended to diagnose, treat, cure, or prevent any disease. Generated by AI. Always verify with a healthcare professional. Educational information only. Not a substitute for professional medical advice.