Manson JE, et al. - Among US men aged ≥ 50 years and women aged ≥ 55 years, researchers investigated the benefits and risks of supplementation with vitamin D₃ (2000 IU/day) and marine n−3 (or omega-3) fatty acids (1 g/day) in the primary prevention of cardiovascular disease and cancer. According to findings, n−3 fatty acids supplementation did not result in a lower incidence of the primary end points of major cardiovascular events and invasive cancer of any type vs placebo. They did not observe excess risks of bleeding or other serious adverse events in this analysis.

Methods

• Major cardiovascular events— a composite of myocardial infarction, stroke, or death from cardiovascular causes—and invasive cancer of any type were the primary end points.
• Individual components of the composite cardiovascular end point, the composite end point plus coronary revascularization (expanded composite of cardiovascular events), site-specific cancers, and death from cancer were included secondary end points.
• The investigators also assessed safety.

Results

• In total, 25,871 participants were randomized, including 5,106 black participants.
• During a median follow-up of 5.3 years, 386 participants in the n−3 group and 419 in the placebo group experienced a major cardiovascular event.
• Invasive cancer was diagnosed among 820 participants in the n−3 group and in 797 in the placebo group.
• The hazard ratios were as follows: for the expanded composite end point of cardiovascular events, 0.93 (95% CI, 0.82-1.04); for total myocardial infarction, 0.72 (95% CI, 0.59-0.90); for total stroke, 1.04 (95% CI, 0.83-1.31); for death from cardiovascular causes, 0.96 (95% CI, 0.76-1.21); and for death from cancer (341 deaths from cancer), 0.97 (95% CI, 0.79 -1.20) in the analyses of key secondary end points.
• The hazard ratio was 1.02 (95% CI, 0.90-1.15) in the analysis of death from any cause (978 deaths overall).
• There were no excess risks of bleeding or other serious adverse events.