Vitamin E

vitamin E · alpha-tocopherol · tocopherol · tocotrienol · d-alpha-tocopherol

Snapshot

Indications	Contraindications
Vitamin E deficiency¹ Ataxia with vitamin E deficiency¹ Nonalcoholic fatty liver disease² Low-density lipoprotein oxidation³ Macular degeneration (combination)¹ Tardive dyskinesia⁴ Oxidative stress biomarkers⁵	Warfarin or other blood thinners⁶ Active chemotherapy or radiotherapy¹

Vitamin E is the collective name for fat-soluble compounds with antioxidant activity, and alpha-tocopherol is the only form recognized to meet human requirements¹. It acts chiefly by limiting oxidation of fats in cell membranes and lipoproteins¹. Supplementation corrects deficiency in fat malabsorption disorders and inherited transfer-protein defects¹. It is also used for oxidative-stress targets: nonalcoholic fatty liver disease, cardiovascular risk, and, within multinutrient formulations, macular degeneration progression¹.

The cardiovascular evidence is discordant: observational studies favor higher intake, but a systematic review found almost all randomized trials showed no benefit⁷. In fatty liver disease, a Cochrane review found likely small reductions in liver enzymes, with clinical impact unknown². A 2025 meta-analysis of clinical trials found supplementation reduced low-density lipoprotein oxidation, a laboratory marker rather than an event outcome³. Products are mostly natural d-alpha or synthetic dl-alpha-tocopherol, often esterified in softgels, with mixed tocopherol and tocotrienol products also sold; see Form comparison¹.

The most consequential caution is bleeding: the National Institutes of Health fact sheet notes that high-dose alpha-tocopherol inhibits platelet aggregation and that two trials found more hemorrhagic stroke¹. Memorial Sloan Kettering Cancer Center lists blood thinners under 'do not take if' and asks for prothrombin time and international normalized ratio monitoring when vitamin E starts or stops⁶.

Last updated October 15, 2026. Read how we make monographs.

In the full monograph

73 sources, 60 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources