Vitamin D Supplementation Does Not Lower Cardiovascular Event Incidence

The following article is part of conference coverage from the 2018 AHA Scientific Sessions in Chicago, Illinois.The Cardiology Advisor’s staff will be reporting breaking news associated with research conducted by leading experts in cardiology. Check back for the latest news from AHA 2018.

CHICAGO — Vitamin D supplementation did not lower the incidence of cancer or cardiovascular events compared with placebo, according to research presented at the American Heart Association Scientific Sessions, held November 10-12, in Chicago and simultaneously published in the New England Journal of Medicine.^1,2

Investigators conducted a nationwide, randomized, placebo-controlled trial (VITAL; ClinicalTrials.gov identifier: NCT01169259) with a 2×2 factorial design to assess whether vitamin D (2000 IU/day) and omega-3 fatty acids (1 g/day) would reduce the risk for cardiovascular disease and cancer in men ≥50 years and women ≥55 years.

Invasive cancer of any type and major cardiovascular events (a composite of myocardial infarction, stroke, or death from cardiovascular causes) were the primary end points. Site-specific cancers, death from cancer, and additional cardiovascular events comprised the secondary end points.

A total of 25,871 participants were randomly assigned to either vitamin D or placebo. The mean age of the participants was 67.1 years and 5106 were black. Cancer was diagnosed in 1617 participants during a median follow-up of 5.3 years (793 in the vitamin D group and 824 in the placebo group; hazard ratio [HR], 0.96; 95% CI, 0.88-1.06; P =.47).

Meanwhile, a major cardiovascular event occurred in 805 individuals (396 in the vitamin D group and 409 in the placebo group; HR, 0.97; 95% CI, 0.85-1.12; P =.69).

In terms of site-specific cancers, the HR for breast cancer was 1.02 (95% CI, 0.79-1.31), 0.88 (95% CI, 0.72-1.07) for prostate cancer, 1.09 (95% CI, 0.73-1.62) for colorectal cancer, and 0.96 (95% CI, 0.86-1.08) for the expanded cardiovascular events end point.

HR for myocardial infarction was 0.96 (95% CI, 0.78-1.19), 0.95 (95% CI, 0.76-1.20) for stroke, and 1.11 (95% CI, 0.88-1.40) for death from cardiovascular causes. The HR for death from any cause was 0.99 (95% CI, 0.87-1.12). There were no increased risks for hypercalcemia or other adverse events.

Strengths of the study included the diversity of the participants (eg, race, ethnicity, and geographic location) as well as high rates of adherence. However, the trial was limited in that only one dose of vitamin D was tested.

“The observed lack of benefit of vitamin D supplementation for cardiovascular outcomes in our trial is consistent with results of previous trials of vitamin D, even at moderate or high doses,” the researchers concluded.

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References

1. Manson JE, Cook NR, Lee I-M, et al; for the VITAL Research Group. Vitamin D supplements and prevention of cancer and cardiovascular disease [published online November 10, 2018]. N Engl J Med. doi: 10.1056/NEJMoa1809944dis
2. Manson JE, Cook NR, Lee I-M, et al. Vitamin D and Omega-3 Trial (VITAL): principal results for vitamin D and omega-3 fatty acid supplementation in the primary prevention of cardiovascular disease and cancer. Presented at: the American Heart Association 2018 Scientific Sessions; November 10-12, 2018; Chicago, IL. Abstract 19539.