Supplement monograph

Calcium

A mineral where diet-first gap review, iron separation, thyroid-medication spacing, and bone-stack context matter more than routine high-dose use.

Practical read

Place calcium away from iron-focused slots and away from thyroid medication unless the prescribing clinician gives a different schedule.

Decision frame

Calcium: what to check before it earns a slot

Timing rule

Place calcium away from iron-focused slots and away from thyroid medication unless the prescribing clinician gives a different schedule.

Form lens

Calcium carbonate: meal-paired common optionCalcium citrate: less meal-dependentFood-first calcium: often the cleaner baseline

Safety lens

Can reduce non-heme iron absorption when taken togetherCan interfere with levothyroxine absorptionTotal intake from food plus supplements matters

Best fit

  • Low-dietary-calcium context
  • Bone-stack review
  • Mineral spacing audits

Form notes

  • Calcium carbonate: meal-paired common option
  • Calcium citrate: less meal-dependent
  • Food-first calcium: often the cleaner baseline

Watchouts

  • Can reduce non-heme iron absorption when taken together
  • Can interfere with levothyroxine absorption
  • Total intake from food plus supplements matters

Sources and next checks

NIH ODS calcium fact sheetMayo Clinic levothyroxine and calcium timing guidance
Calcium and iron timingCalcium and iron interactionCalcium and thyroid medication spacing

Evidence Brief

Get supplement timing and safety notes as they ship.

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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.