Warfarin (Blood Thinner)
Common brand names: Coumadin, Jantoven
Two nutrients listed against this medication. The most severe is marked critical.
At a glance
Neither of the two is marked well documented. Each row carries its own evidence level.
At a glance
- Vitamin K (Important: Complex Interaction)Critical · Moderate evidence
- CoQ10Moderate · Traditionally cited, limited evidence
Color shows how serious each listed effect is. The label beside it shows how strong the evidence is. The cards below explain each one and show its evidence.
Nutrients it can lower
Mechanism, Warfarin works by blocking Vitamin K-dependent clotting factors. This is intentional, but it also impairs Vitamin K2 (MK-7) beneficial effects on arterial calcification and bone. This is a monitored interaction, not a simple depletion.
Common signs, Arterial calcification, bone loss, while INR is maintained for clotting prevention
Schurgers et al. (PLoS One, 2012; PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 22952653): warfarin blocks the vitamin K cycle; in patients this associated with more coronary calcification. Added vitamin K works against warfarin. It opposes the drug. This entry flags the interaction, not a supplement.
Important: vitamin K is not supplemented without prescriber approval, since it alters INR and anticoagulation. The K2 (MK-7) arterial-calcification question is discussed with a cardiologist; some clinicians use very low, consistent K2 doses with careful monitoring.
Mechanism, CoQ10 has a mild Vitamin K-like structure and can reduce warfarin efficacy slightly in some individuals, which is an INR-monitoring question for the prescriber.
Common signs, Altered INR, not a depletion but a monitoring requirement
Spigset (Lancet, 1994): a report of reduced warfarin effect during ubidecarenone (CoQ10) use. The concern here is a drug interaction, not warfarin depleting CoQ10.
Where CoQ10 is used at all on warfarin, 30–60 mg is the low range in common use, not a figure from a trial cited on this row. The cited report describes a reduced warfarin effect during ubidecarenone use, which is why this is a prescriber's decision with INR monitoring rather than a dose to start.
For your next appointment
It prints or saves as a single page. Whether to add a supplement for a nutrient this medication may lower is a decision for your prescriber.
Disclosure
These statements have not been evaluated by the Food and Drug Administration. Any grade on this page describes the strength of published human trial evidence in the populations studied. It is not a recommendation for any individual and is not medical advice. Starting, stopping or changing any supplement or medication is a decision for your physician.
Grades move when new trials publish. A free monthly email lists every grade EBL moved, with the reason and the trial behind it: the sign-up is on the Evidence Log →