Can you take Calcium and Magnesium together?
Above 500 mg combined, these minerals compete for absorption. Separating them improves uptake of both.
Severity
Caution
Evidence
moderate
Timing
Calcium morning, magnesium evening.
How it works
Both share intestinal ion channels including TRPM6 and TRPM7 transporters.
The competition is modest at lower doses but clinically relevant above 500 mg combined. Separating them also aligns with practical timing: magnesium's calming effect suits the evening, while calcium pairs well with morning Vitamin D.
What to do
Calcium with breakfast, magnesium before bed. This avoids competition and plays to each mineral's strength. If using a combined cal-mag supplement, consider switching to separate doses.
Frequently asked
Should I separate Calcium and Magnesium?
Consider separating them. Calcium morning, magnesium evening. Consult a healthcare professional for personalised advice.
Why do Calcium and Magnesium interact?
Both share intestinal ion channels including TRPM6 and TRPM7 transporters.
How strong is the evidence for this interaction?
The evidence is moderate. Some studies support this interaction, but more research may be needed.
About these supplements
Other Calcium interactions
Other Magnesium interactions
Related reading
Check your full stack
for interactions.
See what competes, what combines well, and when to take everything. Every interaction cites a published source.
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6 supplements
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1 flagZinc and Iron compete for the same absorption pathway. Take at least 2 hours apart.
Supplements
This information is for educational purposes only. It is not medical advice and does not diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional.