Vitamin E (alpha-tocopherol) is a fat-soluble antioxidant that protects cell membranes from oxidative damage. Our research shows a cautionary tale: early observational data suggested cardiovascular benefit, but large RCTs found high-dose vitamin E (≥400 IU/day) may INCREASE all-cause mortality. NAFLD and Alzheimer's disease remain the two conditions where vitamin E supplementation has positive evidence. For most healthy adults, supplementation is unnecessary and potentially harmful at high doses.
Vitamin E has anticoagulant properties at >400 IU; increased bleeding risk
Additive antiplatelet effects
Vitamin E may reduce HDL-raising effect of niacin combination therapy
Antioxidant may protect cancer cells from oxidative treatment
May alter cyclosporine metabolism
A 2005 meta-analysis of 135,967 participants found high-dose vitamin E (≥400 IU/day) was associated with increased all-cause mortality (RR 1.04, 95% CI 1.01-1.07) (PMID: 15537682). The effect was dose-dependent. This analysis changed clinical practice and led to recommendations against routine high-dose vitamin E supplementation.
Not Prohibited
Sanyal AJ et al. Pioglitazone, vitamin E, or placebo for NASH (PIVENS trial).
Dysken MW et al. Effect of vitamin E and memantine on functional decline in Alzheimer disease (TEAM-AD trial).
Miller ER et al. Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality.
Lippman SM et al. Effect of selenium and vitamin E on risk of prostate cancer (SELECT trial).
Reviewed by the Scan Dose Research Team and Clinical Advisory Board | Last updated: April 2026
Not medical advice. Based on published clinical research and systematic reviews.
Safety
Moderate interactions. Monitoring, timing separation, or dose adjustment may be required.
Warfarin and other anticoagulants
High-dose vitamin E (over 400 IU) inhibits platelet aggregation.
Source: Clinical pharmacology
Aspirin and NSAIDs
Additive antiplatelet effect.
Source: Clinical consensus
Chemotherapy (alkylating agents)
Vitamin E is an antioxidant that may protect cancer cells from oxidative damage.
Source: Theoretical, debated
Statins combined with niacin
High-dose vitamin E may blunt the HDL-raising effect of the statin-niacin combo.
Source: Limited evidence
Stop 2 weeks before surgery
High-dose bleeding risk.
Educational information only. This is not medical advice. These statements have not been evaluated by the FDA. Talk to your prescriber before starting, stopping, or combining any supplement with prescription medication.