High-dose vitamin E may interfere with vitamin K
Very high doses of vitamin E (>800 IU) can interfere with vitamin K's blood clotting function.
Avoid very high vitamin E doses, especially if on blood thinners.
Moderate doses are fine together
High-dose vitamin E may interfere with vitamin K. Avoid very high vitamin E doses, especially if on blood thinners.
Moderate doses are fine together
This interaction is rated “Caution” by Formulate. Very high doses of vitamin E (>800 IU) can interfere with vitamin K's blood clotting function.
Studies from our registry that mention vitamin e or vitamin k. Each links to the primary source and the other Formulate pages citing it.
Mentions vitamin k · 2016
Interaction Between Dietary Vitamin K Intake and Anticoagulation by Vitamin K Antagonists: Is It Really True? A Systematic Review
Violi et al. · Medicine (Baltimore)
Conflicting evidence on whether dietary vitamin K intake affects warfarin response. Some studies show inverse correlation between vitamin K intake and INR changes. Others suggest a minimum vitamin K intake is REQUIRED for stable anticoagulation. Conclusion: available evidence does NOT support the old advice to restrict dietary vitamin K when starting warfarin. Consistency of intake matters more than absolute level.
Mentions vitamin e · 2012
Silybin combined with phosphatidylcholine and vitamin E in patients with nonalcoholic fatty liver disease
Loguercio C, Andreone P, Brisc C, et al. · Free Radical Biology and Medicine
12-month RCT (n=138) in NAFLD found a silybin-phosphatidylcholine-vitamin E complex reduced insulin resistance and liver enzymes vs placebo, supporting phytosome forms of silymarin for NAFLD.
Mentions vitamin e · 2009
Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)
Lippman SM, Klein EA, Goodman PJ, et al. · JAMA
Large primary-prevention RCT (n=35,533) found selenium 200µg/day did not prevent prostate cancer — and later follow-up raised concerns about increased type 2 diabetes risk at supplemental doses in selenium-replete populations.
Mentions vitamin k · 2007
Effect of fixed-dose vitamin K supplementation on INR stability in warfarin patients
Yamey et al. · BMJ
Daily low-dose vitamin K supplementation resulted in significantly greater decreases in INR standard deviation and greater increases in percentage time within target INR range. Low-dose vitamin K can STABILIZE anticoagulation in patients with variable response.
Mentions vitamin k · 2006
Dietary vitamin K variability affects International Normalized Ratio (INR) coagulation indices
Couris et al. · Int J Vitam Nutr Res
Inverse correlation between variability in INR and changes in vitamin K intake (r = -0.600, p < 0.01). VARIABILITY is the issue, not absolute level.
Other interactions to know
Vitamin K directly antagonizes warfarin. Consistency of intake, not avoidance, is the right clinical approach.
High-dose vitamin E increases warfarin bleeding risk
Vitamin E enhances aspirin's antiplatelet effect
Vitamin E protects omega-3 fats from oxidation
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Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.
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