NutriStack
Vitamin E and Warfarin, a caution.
High-dose vitamin E may potentiate warfarin's anticoagulant effect and increase bleeding risk. Vitamin E at high supplemental doses can interfere with vitamin K-dependent clotting and inhibit platelet aggregation.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Pair type
- Caution
- Evidence (highest tier)
- Moderate
- Source citations
- 6 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Moderate evidence
Caution
What is happening. High-dose vitamin E may potentiate warfarin's anticoagulant effect and increase bleeding risk. Vitamin E at high supplemental doses can interfere with vitamin K-dependent clotting and inhibit platelet aggregation.
Mechanism. High-dose vitamin E inhibits vitamin K-dependent carboxylase, reducing production of functional clotting factors. It also has antiplatelet activity by inhibiting platelet adhesion and aggregation through interference with thromboxane synthesis.
Recommendation. Do not start, stop, or increase vitamin E while taking warfarin without discussing it with the anticoagulation clinic or prescriber. Report unusual bruising or bleeding promptly.
Sources (6)
- Corrigan JJ Jr, Marcus FI. Coagulopathy associated with vitamin E ingestion. JAMA. 1974;230(9):1300-1301. PMID 4479597
- Booth SL et al. Effect of vitamin E supplementation on vitamin K status in adults with normal coagulation status. Am J Clin Nutr. 2004;80(1):143-148. PMID 15213041
- Wang M, Zeraatkar D, Obeda M, Lee M et al.. Drug-drug interactions with warfarin: A systematic review and meta-analysis. British Journal of Clinical Pharmacology. 2021. PMID 33769581
- Xia J, Yu J, Xu H et al.. Comparative effects of vitamin and mineral supplements in the management of type 2 diabetes in primary care: A systematic review and network meta-analysis of randomized controlled trials. Pharmacological Research. 2023. PMID 36638933
- Bayu P, Wibisono JJ. Vitamin C and E antioxidant supplementation may significantly reduce pain symptoms in endometriosis: A systematic review and meta-analysis of randomized controlled trials. PLoS One. 2024. PMID 38820340
- Berger MM, Shenkin A, Schweinlin A et al.. ESPEN micronutrient guideline. Clinical Nutrition. 2022. PMID 35365361
Stack Score
How this pair moves the number.
Effect on the composite score
If both Vitamin E and Warfarin are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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