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Can You Take Vitamin A and Vitamin K2 Together?
Dose or timing may matter
The short answer
High-dose vitamin A interferes with vitamin K2 (menaquinone) function in gamma-carboxylation of osteocalcin and matrix Gla protein, potentially impairing calcium metabolism and bone health.
How to arrange timing
When supplementing vitamin A, ensure adequate vitamin K2 intake to maintain proper carboxylation of vitamin K-dependent proteins.
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.