Can You Take Vitamin A and Vitamin K1 Together?

Dose or timing may matter

The short answer

High-dose vitamin A may antagonize vitamin K function by interfering with vitamin K-dependent carboxylation of clotting factors. Excess retinol has been shown to reduce the biological activity of vitamin K in coagulation.

How to arrange timing

Avoid excessive vitamin A supplementation if vitamin K status is marginal or if on anticoagulant therapy.

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.