NutriStack
Vitamin E and Vitamin K1, a caution.
High-dose vitamin E (>400 IU) can antagonize vitamin K-dependent clotting factor activation, increasing bleeding risk.
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.
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At a glance
- Substances
- Vitamin E and Vitamin K1
- Pair type
- Caution
- Evidence (highest tier)
- Strong
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Caution · Strong evidence
Caution
What is happening. High-dose vitamin E (>400 IU) can antagonize vitamin K-dependent clotting factor activation, increasing bleeding risk.
Mechanism. Alpha-tocopherol at high doses inhibits vitamin K-dependent carboxylase (GGCX), reducing gamma-carboxylation of clotting factors II, VII, IX, and X.
Recommendation. Keep vitamin E under 400 IU if taking K1 for coagulation support or if on anticoagulant therapy. Monitor INR.
Sources (2)
- 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):143-8. PMID 15213041
- Pastori D et al. Vitamin E serum levels and bleeding risk in patients receiving oral anticoagulant therapy: a retrospective cohort study. J Am Heart Assoc. 2013;2(6):e000364. PMID 24166490
Stack Score
How this pair moves the number.
Effect on the composite score
If both Vitamin E and Vitamin K1 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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