Effect of Marine Omega-3 Fatty Acid and Vitamin D Supplementation on Incident Atrial Fibrillation: A Randomized Clinical Trial
RCT (n=25,119) found that both icosapentaenoic acid with docosahexaenoic acid (460/380mg/day) and vitamin D3 (2000 units/day) did not reduce the incidence of AF vs placebo after a median follow up of 5.3 years (both 3.7% vs 3.4% for placebo, p=0.19 for both placebo comparisons).
Source:
Journal of the American Medical Association
SPS commentary:
A related editorial discusses this research and comments that in the past 2 years, 4 randomised clinical trials have provided data on the risk of AF with omega-3 fatty acid intake. Although these studies generally investigated whether omega-3 fatty acids reduced the risk of atrial fibrillation, when the studies are considered together, the data suggest, but do not prove, that there may actually be a dose-related increased risk of AF with omega-3 fatty acid intake. At a dose of 4.0 g/day, there was a highly statistically significant increase in risk (nearly a doubling). With an intermediate dose of 1.8 g/day, the increase in risk (hazard ratio, 1.84) did not achieve statistical significance, and with a standard daily dose of 840 mg/day, there was no apparent increase in risk (although the data were consistent with as much as a 24% increase in risk). Patients who choose to take omega-3 fatty acids, especially in high doses, should be informed of the risk of AF and followed up for the possible development of this common and potentially hazardous arrhythmia.