Vitamin D Supplementation and the Prevention of Cancer and Cardiovascular Disease

N Engl J Med 2019; 380:33-44

DOI: 10.1056/NEJMoa1809944

Commentary

This study investigates whether vitamin D supplementation can reduce the risk of cancer and cardiovascular disease. A national randomized, placebo-controlled trial with a 2 x 2 factorial design of vitamin D was conducted analyzing acid in doses of 1 g per day for the prevention of cancer and cardiovascular disease in men over 50 and women over 55 years of age in the United States, with a dose fat of 2000 IU per day of omega-3 and marine n-3.

The primary endpoint is any type of invasive cancer and major cardiovascular events.

The results, which randomized a total of 25,871 participants, showed that vitamin D supplementation was not associated with a lower risk of either of the primary endpoints.

With a median follow-up of 5 years, 1617 participants were diagnosed with cancer during the 3-year period. (793 in the vitamin D group and 824 in the placebo group; hazard ratio, 0.96; 95% confidence interval [CI], 0.88 to 1.06; P = .47. )

Major cardiovascular events occurred in 805 participants (396 in the vitamin D group and 409 in the placebo group; hazard ratio, 0.97; 95% CI, 0.85-1.12; P = .69), and in the analysis of secondary endpoints, the hazard ratios were

Death from cancer (341 deaths), 0.83 (95% CI, 0.67 to 1.02). For breast cancer, 1.02 (95% CI, 0.79 to 1.31); for prostate cancer, 0.88 (95% CI, 0.72 to 1.07); for colorectal cancer, 1.09 (95% CI, 0. 73 to 1.62); for the expanded composite endpoint of major cardiovascular events and coronary revascularization , 0.96 (95% CI, 0.86 to 1.08). For myocardial infarction, 0.96 (95% CI, 0.78-1.19); for stroke, 0.95 (95% CI, 0.76-1.20); for death from cardiovascular causes, 1.11 (95% CI, 0.88-1.40).

The results of this analysis show that vitamin D supplementation does not reduce the incidence of invasive cancer and cardiovascular events more than placebo.