Some observational studies suggest that vitamin D and marine omega-3 fatty acids may be associated with a lower risk of developing AMD; however, there’s limited evidence from randomized trials. A recent, large-scale randomized trial took on this gap in the literature and found the supplements had no significant effect on AMD incidence or progression.

The randomized, placebo-controlled clinical trial was an ancillary study of the Vitamin D and Omega-3 Trial (VITAL), a nationwide study on the potential effects of these supplements in preventing cancer and cardiovascular disease. For AMD study purposes, the researchers included 25,871 adults taking vitamin D3 (2,000IU) and omega-3 fatty acids (1g) daily for a median of 5.3 years.

The participants were around 67 years of age (50.6% female, 71.3% white and 20.2% Black). Over the course of the study follow-up period, 324 participants experienced an AMD event (285 incident AMD and 39 progression to advanced AMD). Those taking vitamin D3 experienced 163 AMD events, while the placebo group experienced 161. In the omega-3 group, 157 AMD events occurred compared with 167 in the placebo group.

The researchers reported hazard ratios in the vitamin D3 group of 1.09 for incident AMD and 0.63 for AMD progression. In the omega-3 group, they reported 0.93 for incident AMD and 1.05 for AMD progression. They concluded that neither supplement had a significant effect on AMD.

Christen WG, Cook NR, Manson JE, et al. Effect of vitamin D and omega-3 fatty acid supplementation on risk of age-related macular degeneration: An ancillary study of the VITAL randomized clinical trial. JAMA Ophthalmol. October 29, 2020. [Epub ahead of print].