Mild interactionMildSeparate by 2h

Calcium citrate and Magnesium glycinate: interaction, severity and spacing

Calcium citrate and Magnesium glycinate interact because high-dose calcium and magnesium share absorptive pathways and compete to a modest degree; the interaction is only meaningful at large supplemental doses. Take them 2 hours apart. Mild risk.

Last reviewed: 2026-09-20Reviewed by: StackingRight clinical review

The interaction in detail

Summary of the Calcium citrate and Magnesium glycinate interaction
PairCalcium citrate and Magnesium glycinate
TypeNutrient interaction
SeverityMild
Required spacing2 hours minimum
OnsetAt the time of dosing

Mechanism

High-dose calcium and magnesium share absorptive pathways and compete to a modest degree; the interaction is only meaningful at large supplemental doses.

What to do

If you take more than 500 mg of either, separate them by about 2 hours. Small doses together are fine.

How to fit both into one day

Calcium citrate
middaywith food

Calcium absorbs better with food and in doses at or below 500 mg. Take it with vitamin D3, and separate it from iron, zinc and thyroid medication.

Magnesium glycinate
eveningflexible

Magnesium supports parasympathetic tone and muscle relaxation, so evening dosing also helps sleep. Keep it two hours from antibiotics and thyroid medication.

Putting Calcium citrate in the midday and Magnesium glycinate in the evening satisfies the 2-hour separation without disrupting either one's absorption window.

Calcium citrate and Magnesium glycinate: common questions