Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration.

Participants: people with age-related macular degeneration (AMD) in one or both eyes; average age about 72 years; slightly more women (~56%); study designs: randomized controlled trials (parallel-group; AREDS included a 2x2 factorial design); settings included ophthalmology clinics and population samples; trials spanned early to late AMD.

Zinc sulfate 200 mg daily; zinc oxide 80 mg daily; zinc monocysteine 25 mg daily; broad-spectrum antioxidant formulations (Ocuguard; Visaline) versus placebo; Vitamin E alone (VE-CAT) at 500 IU daily; AREDS regimen in 2x2 factorial design: placebo; zinc alone; antioxidants (Vitamin C 500 mg; Vitamin E 400 IU; beta-carotene 15 mg) alone; zinc plus antioxidants; lutein-containing regimens: Lutein 20 mg daily for 3 months then 10 mg daily for 3 months (LISA); lutein plus broad-spectrum antioxidant (OcuPower) versus lutein alone; Bartlett 2007 antioxidant formulation: lutein 6 mg; retinol 750 μg; vitamin C 250 mg; vitamin E 34 mg; zinc 10 mg; copper 0.5 mg; CARMIS formulation: vitamin C 180 mg; vitamin E 30 mg; zinc 22.5 mg; copper 1 mg; lutein 10 mg; zeaxanthin 1 mg; astaxanthin 4 mg; Newsome 2008 zinc-monocysteine 25 mg; Chinese trial (Wang 2004): zinc oxide 80 mg daily plus vitamin C and vitamin E (doses not reported). Durations ranged from 6 months to about 7 years.

Antioxidant vitamin and mineral supplementation can modestly delay AMD progression, with strongest evidence from AREDS. AREDS showed antioxidants plus zinc reduced progression to advanced AMD (odds ratio 0.68; 95% CI 0.53–0.87) and reduced loss of 15 letters of distance visual acuity (OR 0.77; 95% CI 0.62–0.96). Other regimens yielded less consistent or smaller benefits; some showed little or no improvement in continuous visual acuity measures. Adverse effects included yellow skin coloration with antioxidants and higher anemia with zinc; one trial noted more hospital admissions with zinc. Practical takeaway: AMD patients may experience a modest delay in progression with antioxidant–mineral supplements, particularly AREDS-like regimens; generalizability requires replication; maintain a healthy diet; further trials needed to confirm safety and effectiveness across populations.

Most trials were small or of short duration; regimens and outcome measures were heterogeneous; reliance on AREDS for most positive effects; some trials had incomplete reporting or potential biases; generalizability to diverse populations remains uncertain.