Purpose: To test whether long-term multivitamin supplementation affects the incidence of cataract or age-related macular degeneration (AMD) in a large cohort of men.
Design: Randomized, double-blind, placebo-controlled trial.
Participants: A total of 14,641 US male physicians aged ≥ 50 years.
Intervention: Daily multivitamin or placebo.
Main outcome measures: Incident cataract and visually significant AMD responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-reports confirmed by medical record review.
Results: During an average of 11.2 years of treatment and follow-up, a total of 1817 cases of cataract and 281 cases of visually significant AMD were confirmed. There were 872 cataracts in the multivitamin group and 945 cataracts in the placebo group (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.83-0.99; P = 0.04). For visually significant AMD, there were 152 cases in the multivitamin group and 129 cases in the placebo group (HR, 1.19; 95% CI, 0.94-1.50; P = 0.15).
Conclusions: These randomized trial data from a large cohort of middle-aged and older US male physicians indicate that long-term daily multivitamin use modestly and significantly decreased the risk of cataract but had no significant effect on visually significant AMD.
Trial registration: ClinicalTrials.gov NCT00270647.
Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.