Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality.

Area of Science:

• Nutritional Science
• Clinical Trials
• Public Health

Background:

• Observational studies and experimental models suggest potential benefits of vitamin E for cardiovascular disease and cancer prevention.
• However, some trials indicate a non-statistically significant increase in total mortality with high-dose vitamin E supplementation.

Purpose of the Study:

• To conduct a meta-analysis examining the dose-response relationship between vitamin E supplementation and total mortality.
• Utilizing data from randomized, controlled trials to assess this relationship.

Main Methods:

• A comprehensive literature search of PubMed and the Cochrane Clinical Trials Database was performed (1966-August 2004).
• Data from 19 randomized, controlled trials involving 135,967 participants were analyzed.
• Dosages of vitamin E ranged from 16.5 to 2000 IU/d, with a median of 400 IU/d.

Main Results:

• Nine of eleven trials using high-dose vitamin E (≥400 IU/d) showed an increased risk of all-cause mortality.
• A pooled analysis of high-dose trials revealed a mortality risk difference of 39 per 10,000 persons (P=0.035).
• A statistically significant dose-response relationship was observed, with increased mortality risk noted at dosages exceeding 150 IU/d.

Conclusions:

• High-dose vitamin E supplementation (≥400 IU/d) is associated with an increased risk of all-cause mortality.
• The findings, primarily from trials in patients with chronic diseases, may not be generalizable to healthy adults.
• It is recommended to avoid high-dose vitamin E supplements due to potential increased mortality risks.