Vitamins for age-related macular degeneration demonstrate minimal differences.

Evidence The largest multicentre, double-blind, placebo-controlled RCT of 4757 patients with AMD1 examined the effects of antioxidants (500 mg of vitamin C, 400 IU of vitamin E, and 15 mg of beta-carotene); zinc (80 mg of zinc oxide); and antioxidants in combination with zinc on AMD progression. • Mean age 69 years; 56% females; 6.3 years follow-up. • Baseline retinal photography classified patients in categories 1 (minimal) to 4 (advanced). Outcomes: • For 15-letter visual acuity loss: -Pooled together, category 2, 3, and 4 patients had no significant improvement with any intervention. -Category 3 and 4 patients had statistically significantly reduced visual loss for antioxidants with zinc (23%) versus placebo (29%); NNT = 17 (P = .008). • For progression to advanced AMD (predominantly neovascularization): -Category 3 and 4 patients had statistically significantly reduced progression with zinc (NNT = 17, P = .008) and antioxidants with zinc (NNT = 13, P = .001). Limitations: • Category 1 patients (23% of sample) were excluded, reporting was selective, adjustments were made for baseline characteristics, and the trial was industry supported. • Inconsistent results seen in shorter, smaller studies.2