There is no evidence from RCTs that supplementation with antioxidant vitamins (beta-carotene, vitamin C or vitamin E) prevents or slows the progression of age-related cataract. We do not recommend any further studies to examine the role of antioxidant vitamins beta-carotene, vitamin C and vitamin E in preventing or slowing the progression of age-related cataract. Costs and adverse effects should be weighed carefully with unproven benefits before recommending their intake above recommended daily allowances.
Vitamin E and age-related cataract in a randomized trial of women.
To investigate whether vitamin E supplementation decreases the risk of age-related cataract in women.
                Randomized, double-masked, placebo-controlled trial.
                Thirty-nine thousand eight hundred seventy-six apparently healthy female health professionals aged 45 years or older.
                Participants were assigned randomly to receive either 600 IU natural-source vitamin E on alternate days or placebo and were followed up for presence of cataract for an average of 9.7 years.
                Age-related cataract defined as an incident, age-related lens opacity, responsible for a reduction in best-corrected visual acuity to 20/30 or worse, based on self-report and confirmed by medical record review.
                There was no significant difference between the vitamin E and placebo groups in the incidence of cataract (1159 vs. 1217 cases; relative risk [RR], 0.96; 95% confidence interval [CI], 0.88-1.04). In subgroup analyses of subtypes, there were no significant effects of vitamin E on the incidence of nuclear (1056 vs. 1127 cases; RR, 0.94; 95% CI, 0.87-1.02), cortical (426 vs. 461 cases; RR, 0.93; 95% CI, 0.81-1.06), or posterior subcapsular cataract (357 vs. 359 cases; RR, 1.00; 95% CI, 0.86-1.16). Results were similar for extraction of cataract and subtypes. There was no modification of the lack of effect of vitamin E on cataract by baseline categories of age, cigarette smoking, multivitamin use, or several other possible risk factors for cataract.
                These data from a large trial of apparently healthy female health professionals with 9.7 years of treatment and follow-up indicate that 600 IU natural-source vitamin E taken every other day provides no benefit for age-related cataract or subtypes.