Researchers found that fish oil does not reduce the risk of developing atrial fibrillation, the most common disturbance of heart rhythm. Similarly, vitamin D supplements have no protective effect against arrhythmias. The findings were published in JAMA.
Albert CM, Cook NR, Pester J, et al. Effect of marine omega-3 fatty acid and vitamin D supplementation on incident atrial fibrillation: A randomized clinical trial. JAMA. 2021;325(11):1061-1073. doi:10.1001/jama.2021.1489