Vitamin E in the primary prevention of rheumatoid arthritis: the Women's Health Study

Vitamin E supplements may reduce the risk of developing rheumatoid arthritis (RA) through antioxidant effects. Although previous observational studies have investigated this question, no randomized trial data are available.

The Women's Health Study is a randomized, double-blind, placebo-controlled trial designed to evaluate the benefits and risks of low-dose aspirin and vitamin E in the primary prevention of cardiovascular disease and cancer among 39,876 female health professionals age > or = 45 years throughout the US, conducted between 1992 and 2004. After excluding women with self-reported RA at baseline, 39,144 women were included in the present study. The primary end point, definite RA, was confirmed using a connective tissue disease screening questionnaire, followed by medical record review for American College of Rheumatology criteria.

During an average followup of 10 years, 106 cases of definite RA occurred, 50 in the vitamin E group and 56 in the placebo group. Sixty-four (60%) RA cases were rheumatoid factor positive and 42 (40%) were rheumatoid factor negative. There was no significant association between vitamin E and risk of definite RA (relative risk [RR] 0.89, 95% confidence interval [95% CI] 0.61-1.31). There were also no significant risk reductions for either seropositive RA (RR 0.64, 95% CI 0.39-1.06) or seronegative RA (RR 1.47, 95% CI 0.79-2.72).

Six hundred IU of vitamin E supplements taken every other day is not associated with a significant reduction in the risk of developing RA among women in a randomized, double-blind, placebo-controlled trial.