NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated August 1, 2026

Supplement × Prescription·Evidence index

Vitamin E and Warfarin: what the published research says

PubMed indexes 8 records that name Vitamin E and Warfarin together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.

Read this first

An evidence index, not guidance.

Every statement below is attributed to a named, dated, linked source.

This page lists published research relevant to Vitamin E and Warfarin. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.

The research

8 studies naming Vitamin E and Warfarin.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Effect of vitamin E on the anticoagulant response to warfarin.

The American journal of cardiology · 1996 · PMID 8629604

Clinical TrialRandomized Controlled Trial

“To clarify whether vitamin E enhances the pharmacologic effect of warfarin, we completed a double-blind clinical trial in which 21 subjects taking chronic warfarin therapy were randomized to receive either vitamin E or placebo. None of the subjects who received vitamin E had a significant change in the international normalized ratio, and thus it appears that vitamin E can safely be given to patients who require chronic warfarin therapy.”

Kim et al. · From the abstract

Names both Vitamin E and Warfarin in its title.

Effect of vitamin E on prothrombin levels in warfarin-induced vitamin K deficiency.

The American journal of clinical nutrition · 1981 · PMID 7282596

Clinical TrialRandomized Controlled Trial

“These data suggest that vitamin E acts at the step mediated by vitamin K and not in the synthesis of the factor II precursor. Although the administration of high doses of vitamin E in animals, and possibly humans, with vitamin K deficiency potentiates the vitamin K deficiency, this effect is not clinically obvious with 400 IU/day or less.”

Corrigan et al. · From the abstract

Names both Vitamin E and Warfarin in its title.

Ask the doctor. I am 95 years old and recently began treatment for early macular degeneration in one eye. My retinologist said that PreserVision might help protect the other eye. But she cautioned that it contains a large dose of vitamin E, which could cause a bleeding problem with the Coumadin I take because of a mechanical aortic valve. What would you suggest?

Harvard heart letter : from Harvard Medical School · 2010 · PMID 20590010

Human subjects

Names both Vitamin E and Warfarin in its title.

The effect of vitamin E on warfarin-induced vitamin K deficiency.

Annals of the New York Academy of Sciences · 1982 · PMID 6959563

Human subjects

“Factor II antigen as determined by electroimmunoassay in humans and factor II coagulant activity as measured using Echis venom in animals were unchanged and no different from untreated controls. The data suggest that vitamin E acts at the vitamin K-carboxylase step of carboxylation of precursor prothrombin and not in the synthesis of the precursor protein.”

Corrigan · From the abstract

Names both Vitamin E and Warfarin in its title.

Interactions of commonly used dietary supplements with cardiovascular drugs: a systematic review.

Systematic reviews · 2012 · PMID 22651380

Systematic ReviewHuman subjects

“Evidence of low-strength indicates benefits of omega-3 fatty acids (plus statin, or calcium channel blockers and antiplatelets) and garlic (plus nitrates or warfarin) on triglycerides and HDL-C, respectively. Safety concerns, however, persist.”

Kanji et al. · Authors' conclusion

Names Vitamin E and Warfarin together in an interaction, co-administration, or pharmacokinetic context.

Effective and safe modification of multiple atherosclerotic risk factors in patients with peripheral arterial disease.

American heart journal · 2000 · PMID 11054628

Clinical TrialRandomized Controlled Trial

“ADMIT demonstrates that it is both feasible and safe to modify multiple atherosclerotic disease risk factors effectively with intensive combination therapy in patients with PAD.”

Garg et al. · Authors' conclusion

Names Vitamin E and Warfarin together in an interaction, co-administration, or pharmacokinetic context.

Limitations

What this evidence cannot tell you.

Search-based evidence indexes have real limits, and it is worth being explicit about them:

NutriStack

Track what you actually take.

NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Vitamin E, Warfarin, and several hundred other substances.

The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.