Can You Take Selenium and Vitamin C Together?

Dose or timing may matter

The short answer

High-dose vitamin C may reduce selenite (inorganic selenium) to elemental selenium in the GI tract, rendering it biologically unavailable. This redox interaction specifically affects selenite forms.

How to arrange timing

Take selenium and high-dose vitamin C at different times; selenomethionine forms are less affected.

Reference

Reference noted for this combination: Ip C, Lisk DJ. Bioactivity of selenium from Brazil nut for cancer prevention and selenoenzyme maintenance. Nutr Cancer. 1994;21(3):203-212

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.