Large prevention trials studied natural vitamin E 400 IU/day for years but do not support cardiovascular or cancer prevention
Reviewed · Published
Vitamin E
Alpha-tocopherol activity protects membrane lipids from oxidation.
Established functions
- Alpha-tocopherol activity protects membrane lipids from oxidation.
Dietary sources
- almonds
- sunflower oil
- avocado
Claims and evidence
Claims that Vitamin E alone prevents or treats disease, or invariably improves health without deficiency, are unsupported.
Japanese reference amounts
- Japanese adults (age and sex as specified): Adult men 6.0–7.0 mg/day; women 5.0–6.0 mg/day (AI)
Amounts studied
- Large prevention trials studied natural vitamin E 400 IU/day for years but do not support cardiovascular or cancer prevention
Tolerable upper limits
- Adults: 700–850 mg/day alpha-tocopherol
Forms and bioavailability
Supplement forms: natural RRR-alpha-tocopherol, synthetic all-rac-alpha-tocopherol
- Fat-soluble and bile-dependent; natural and synthetic forms have different activity conversions.
Safety and interactions
Adverse effects
- bleeding tendency at high doses
- gastrointestinal symptoms
Medicine and nutrient interactions
- warfarin, antiplatelets, vitamin K
Contraindications and cautions
- Avoid high doses with bleeding disorders, before surgery, or during anticoagulation.
Practical selection
- Compare Vitamin E amount per serving, form, allergens, and batch testing; prefer a single-ingredient product suited to the intended use.
Sources and review
- Dietary Reference Intakes for Japanese (2025)Ministry of Health, Labour and Welfare (Japan)
- NIH ODS vitamin fact sheetsNIH Office of Dietary Supplements
Daiki Minaki (editorial and evidence review) ·