Can You Take Menaquinone-4 (MK-4) and Vitamin A Together?

Dose or timing may matter

The short answer

High-dose vitamin A interferes with vitamin K2 function in gamma-carboxylation of osteocalcin and matrix Gla protein. MK-4 (menaquinone-4) is the dominant tissue form of K2, and its function in calcium metabolism may be impaired by excess retinol.

How to arrange timing

Ensure adequate MK-4 intake when supplementing vitamin A, especially at doses above 10,000 IU.

Reference

Reference noted for this combination: Masterjohn C. Vitamin D toxicity redefined: vitamin K and the molecular mechanism. Med Hypotheses. 2007;68(5):1026-1034

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.