Omega 3 and vitamin D supplements don't prevent or delay macular degeneration: JAMA

Also observational studies done in past suggest that higher intake or blood levels of vitamin D and marine Omega 3 fatty acids may be associated with lower risks of age-related macular degeneration (AMD). But evidence from randomized trials is limited

Recently researchers have found in an ancillary Study of the VITAL Randomized Clinical Trial that supplementation of vitamin D or omega-3 fatty acids does not lower the risk for age-related macular degeneration (AMD) or its progression,

The study has appeared in JAMA Ophthalmology .

They conducted a nationwide, placebo-controlled, randomized clinical trial to evaluate whether daily supplementation for approximately 4 to 6 years with vitamin D, marine Omega-3 fatty acids, or both vs placebo prevents the development or progression of age-related macular degeneration in initially healthy US adults.

In a prespecified ancillary study of the Vitamin D and Omega-3 Trial (VITAL) , the researchers randomised over 25,000 U.S. adults aged 50 and older to receive vitamin D supplementation (2000 IU/day) plus marine omega-3 fatty acids (1 g/day), vitamin D plus placebo, omega-3s plus placebo, or double placebo.Randomization was from November 2011 to March 2014, and study pill-taking ended as planned on December 31, 2017.

The primary end point was total age-related macular degeneration (AMD) events, a composite of incident cases of age-related macular degeneration (AMD) plus cases of progression to advanced AMD among participants with AMD at baseline, based on self-report confirmed by medical record review. Analyses were conducted using the intention-to-treat population.

The researchers found that for vitamin D₃, there were 163 events in the treated group and 161 in the placebo group . For Omega -3 fatty acids, there were 157 events in the treated group and 167 in the placebo group . In analyses of individual components for the primary end point, HRs comparing vitamin D₃ groups were 1.09 (95% CI, 0.86-1.37) for incident AMD and 0.63 (95% CI, 0.33-1.21) for AMD progression. For Omega-3 fatty acids, HRs were 0.93 (95% CI, 0.73-1.17) for incident AMD and 1.05 (95% CI, 0.56-1.97) for AMD progression.

During a median 5 years of treatment, 1.3% of participants experienced either incident AMD or worsening of preexisting AMD. Outcomes did not differ significantly regardless of whether participants received vitamin D, omega-3s, or placebo.

The researchers concluded that vitamin D₃ or marine ω-3 fatty acid supplementation didn't have a significant overall effect on AMD incidence or progression.They note that prior observational studies suggested a potential benefit for vitamin D in age-related macular degeneration (AMD), but such studies could have been limited by residual confounding. , "These negative results of a large, well-designed, and well-conducted clinical trial, performed by highly experienced investigators, [are] discouraging."writes a commentator.

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JAMA Ophthalmol. Published online October 29, 2020. doi:10.1001/jamaophthalmol.2020.4409