Vitamin K2 (MK-7) and Warfarin: interaction, severity and spacing
Vitamin K2 (MK-7) and Warfarin interact because warfarin blocks vitamin K epoxide reductase. Adding vitamin K restores clotting factor synthesis and directly antagonises the drug, which can drop the INR into a clot-risk range. Take them with care. Severe risk.
The interaction in detail
| Pair | Vitamin K2 (MK-7) and Warfarin |
|---|---|
| Type | Nutrient–drug interaction |
| Severity | Severe |
| Required spacing | None specified |
| Onset | At the time of dosing |
Mechanism
Warfarin blocks vitamin K epoxide reductase. Adding vitamin K restores clotting factor synthesis and directly antagonises the drug, which can drop the INR into a clot-risk range.
What to do
Do not start vitamin K1 or K2 without telling your prescriber. If you take it, the dose must stay consistent and the INR must be monitored.
How to fit both into one day
Take K2 with vitamin D3 and fat. If you take warfarin, do not add K2 without prescriber involvement.
An evening dose is conventional so the INR drawn the next morning reflects a stable interval. Keep vitamin K intake consistent.
Putting Vitamin K2 (MK-7) in the midday and Warfarin in the evening satisfies the 0-hour separation without disrupting either one's absorption window.