Can You Take Magnesium and Vitamin D2 Together?

Dose or timing may matter

The short answer

Magnesium is required as a cofactor for vitamin D metabolism — it is needed by the enzymes that convert vitamin D to its active form (1,25-dihydroxyvitamin D). Vitamin D2 supplementation without adequate magnesium may result in suboptimal activation and increased magnesium depletion.

How to arrange timing

Ensure adequate magnesium intake (300-400 mg/day) when supplementing vitamin D2 for optimal activation.

Reference

Reference noted for this combination: Uwitonze AM, Razzaque MS. Role of magnesium in vitamin D activation and function. J Am Osteopath Assoc. 2018;118(3):181-189

Important context

Whether supplements suit you together also depends on dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.