BACKGROUND:

Vitamin E at a dose of 2,000 IU per day has been shown to delay Alzheimer's disease (AD) progression, but recent studies have questioned the safety of this dose level and the overall efficacy of vitamin E in AD treatment.

METHODS:

We analyzed the survival history of 847 probable or mixed AD patients followed in a research center between 1990 and the censoring date of December 31, 2004. Standard practice during this period was to recommend vitamin E at 1,000 IU twice daily to all patients. We used Cox proportional hazards modeling to assess the association of vitamin E alone, or in combination with a cholinesterase inhibitor (ChEI), with all-cause mortality, adjusting for important covariates. Approximately two thirds of the patients took vitamin E with a ChEI, 10% took vitamin E alone, and 15% took no antidementia drug.

RESULTS:

The adjusted hazard ratio (HR) associated with vitamin E (with or without a ChEI) was 0.71 (95% CI: 0.57-0.89; p = 0.003). Compared to the no drug treatment group, the HR for vitamin E alone or with another drug was 0.77 (95% CI: 0.60-1.0); the HR for ChEI use alone was 1.2 (95% CI: 0.87-1.60).

CONCLUSION:

The results do not support a concern over increased mortality with high-dose vitamin E supplementation.