Can You Take Menadione (Vitamin K3) and Vitamin A Together?

Dose or timing may matter

The short answer

High-dose vitamin A may antagonize vitamin K function, including menadione (vitamin K3), by interfering with vitamin K-dependent carboxylation of clotting factors. Menadione's lower biological potency compared to K1/K2 makes this antagonism more impactful.

How to arrange timing

Avoid high-dose vitamin A if relying on menadione for vitamin K activity. Ensure adequate vitamin K status.

Reference

Reference noted for this combination: Booth SL et al. Vitamin K: food composition and dietary intakes. Food Nutr Res. 2012;56:5505

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.