Christen WG, Cook NR, Manson JE, et al. - In this randomized clinical trial involving 25,871 adult US men and women, researchers sought to determine whether the development or progression of age-related macular degeneration (AMD) is prevented by daily supplementation with vitamin D₃, marine ω-3 fatty acids, or both. A total of 25,871 candidates with a mean (SD) age of 67.1 (7.0) years were involved in the trial. Three hundred twenty-four participants experienced an AMD event (285 incident AMD and 39 progression to advanced AMD) during a median (range) of 5.3 (3.8-6.1) years of treatment and follow-up. The authors concluded that neither vitamin D₃ nor marine ω-3 fatty acid supplementation had a major overall impact on the incidence or progression of AMD.