The VITAL trial found no effect of vitamin D on its primary composite cardiovascular outcome, but found a strong effect on specific secondary outcomes like heart attack versus stroke.
"the big VITAL study, which was a vitamin D and did a huge study. Yes, there was no effect on the primary outcome, which was looking at all combined cardiovascular-related events. However, when you specifically looked at heart—like heart attack versus stroke, there was a strong effect." (said at 1:00:22)
In the VITAL randomized controlled trial (25,871 participants), vitamin D supplementation (2000 IU/day) showed no significant effect on either the primary composite cardiovascular end point (HR 0.97; 95% CI, 0.85–1.12) or specific secondary cardiovascular end points, including myocardial infarction (HR 0.96; 95% CI, 0.78–1.19) and stroke (HR 0.95; 95% CI, 0.76–1.20). The speaker appears to have conflated the vitamin D arm with the trial's marine omega-3 fatty acid arm, which did observe a significant reduction in myocardial infarction (HR 0.72; 95% CI, 0.59–0.90) alongside a null effect on stroke (HR 1.04; 95% CI, 0.83–1.31).
- contradicts: Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease. (The New England journal of medicine 2019)
"A major cardiovascular event occurred in 805 participants (396 in the vitamin D group and 409 in the placebo group; hazard ratio, 0.97; 95% CI, 0.85 to 1.12; P=0.69). In the analyses of secondary end points, the hazard ratios were as follows: ... for myocardial infarction, 0.96 (95% CI, 0.78 to 1.19); for stroke, 0.95 (95% CI, 0.76 to 1.20)" (abstract, results, passage verified)
pubmedfull study (doi) - context: Marine n-3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer. (The New England journal of medicine 2019)
"In the analyses of key secondary end points, the hazard ratios were as follows: for the expanded composite end point of cardiovascular events, 0.93 (95% CI, 0.82 to 1.04); for total myocardial infarction, 0.72 (95% CI, 0.59 to 0.90); for total stroke, 1.04 (95% CI, 0.83 to 1.31)" (abstract, results, passage verified)
pubmedfull study (doi)