Vitamin D and Omega-3 Trial (VITAL Rhythm Study)

The VITamin D and OmegA-3 TriaL (VITAL) is an ongoing randomized clinical trial of 25,871 U.S. men and women investigating whether taking daily dietary supplements of vitamin D3 (2000 IU) or omega-3 fatty acids (Omacor® fish oil, 1 gram) reduces the risk of developing cancer, heart disease, and stroke in individuals who do not have a prior history of these illnesses. The purpose of this ancillary study is to ascertain and adjudicate atrial fibrillation (AF) outcomes for the primary aim of testing whether omega-3 fatty acid and/or vitamin D supplementation influence atrial fibrillation risk in the general population. We also plan to examine how these agents might impact the development of AF subtypes (persistent versus paroxysmal), intermediate phenotypes for heart rhythm disorders (electrocardiographic parameters), as well as explore effects on arrhythmic death and whether baseline blood levels and/or race modify treatment effects.