Can you take Magnesium and Vitamin D3 together?
Magnesium is required by the enzymes that convert Vitamin D to its active form. Without enough magnesium, D3 supplementation may underperform.
Severity
Info
Evidence
strong
Timing
Together or same day, no conflict.
How it works
Magnesium is a cofactor for CYP2R1 and CYP27B1, the hydroxylase enzymes that convert 25(OH)D to active 1,25(OH)₂D.
Up to 50% of the population may be magnesium-insufficient, which partly explains poor responses to D3 supplementation. Correcting magnesium status can improve serum 25(OH)D without increasing the D3 dose.
What to do
Take both on the same day. If D3 supplementation hasn't moved your blood levels, adding magnesium may help. Glycinate and citrate are well-absorbed forms.
Frequently asked
Should I separate Magnesium and Vitamin D3?
This is an informational interaction. Magnesium and Vitamin D3 are generally fine to take together. Magnesium activates Vitamin D
Why do Magnesium and Vitamin D3 interact?
Magnesium is a cofactor for CYP2R1 and CYP27B1, the hydroxylase enzymes that convert 25(OH)D to active 1,25(OH)₂D.
How strong is the evidence for this interaction?
The evidence is strong, supported by multiple published studies and clinical data.
About these supplements
Other Magnesium interactions
Other Vitamin D3 interactions
Related reading
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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.