NutriStack
Vitamin C Liposomal and Warfarin, a conflict.
High-dose vitamin C has rare case-report evidence of reducing warfarin response, followed by rapid INR increases after vitamin C is stopped. Liposomal vitamin C products are often used at higher supplemental doses, so the same ascorbic acid concern is relevant even though the liposomal form itself has not been separately studied. The main risk is unstable anticoagulation when large vitamin C doses are started, stopped, or changed.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Vitamin C Liposomal and Warfarin
- Pair type
- Conflict
- Evidence (highest tier)
- Emerging
- Source citations
- 2 sources
- Stack Score effect
- −10 to your Stack Score (per scored conflict row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Conflict · Emerging evidence
Conflict
What is happening. High-dose vitamin C has rare case-report evidence of reducing warfarin response, followed by rapid INR increases after vitamin C is stopped. Liposomal vitamin C products are often used at higher supplemental doses, so the same ascorbic acid concern is relevant even though the liposomal form itself has not been separately studied. The main risk is unstable anticoagulation when large vitamin C doses are started, stopped, or changed.
Mechanism. The mechanism of ascorbic acid-associated warfarin resistance is uncertain and may vary by patient. Reported cases show a pharmacodynamic pattern of subtherapeutic INR during ascorbic acid exposure and INR rise after discontinuation.
Recommendation. Keep vitamin C Liposomal dosing consistent if you take warfarin, and avoid high-dose use unless your anticoagulation clinic knows. Check INR after starting, stopping, or substantially changing the dose. Watch for both clot symptoms while INR is low and bleeding symptoms if vitamin C is stopped and INR rebounds.
Sources (2)
- Sattar A, Willman JE, Kolluri R. Possible warfarin resistance due to interaction with ascorbic acid: case report and literature review. Am J Health Syst Pharm. 2013;70(9):782-786. PMID 23592361
- Gao P, Shen Y, Wu P, Lv W. Ascorbic acid-induced warfarin resistance after breast cancer surgery: a case report and literature review. Front Pharmacol. 2024;15:1390996. PMID 38738175
Stack Score
How this pair moves the number.
Effect on the composite score
If both Vitamin C Liposomal and Warfarin are in the same stack, this pair applies −10 to your Stack Score (per scored conflict row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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