Can You Take Phosphorus and Vitamin D3 Together?

Dose or timing may matter

The short answer

High phosphorus intake suppresses 1-alpha-hydroxylase activity in the kidney, reducing the conversion of 25(OH)D to active 1,25-dihydroxyvitamin D3, thereby diminishing vitamin D's biological effects.

How to arrange timing

Maintain balanced phosphorus intake when supplementing vitamin D; avoid excessive phosphorus from supplements.

Reference

Reference noted for this combination: Portale AA et al. Effect of dietary phosphorus on circulating concentrations of 1,25-dihydroxyvitamin D. J Clin Invest. 1989;83(5):1494-1499

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.