Vitamin D Supplementation and Major Cardiovascular Events: D-Health Randomized Controlled Trial
Neale RE, Baxter C, Romero BD, McLeod DSA, English DR, Armstrong BK, Ebeling PR, Hartel G, Kimlin MG, O'Connell R, van der Pols JC, Venn AJ, Webb PM, Whiteman DC, Waterhouse M
Published in BMJ
Abstract
Large Australian RCT of 21,315 participants over 5 years testing monthly vitamin D (60,000 IU) vs placebo. No significant effect on major cardiovascular events. Suggests supplementation may not benefit those with adequate baseline levels but doesn't address deficiency correction.
Methodology
Randomised, double-blind, placebo-controlled trial in Australian adults aged 60-84; monthly oral vitamin D3 60,000 IU versus placebo for up to 5 years; primary outcome for this analysis was major cardiovascular events ascertained from administrative health records.
Key Findings
Major cardiovascular events occurred in 6.0% of the vitamin D group versus 6.6% of placebo (HR 0.91, 95% CI 0.81-1.01) - a difference that did not reach statistical significance. Rates of myocardial infarction (HR 0.81) and coronary revascularisation (HR 0.89) were lower in the vitamin D group, while stroke rates were similar. Absolute risk difference was about 5.8 fewer events per 1,000 participants.
Conclusions
Monthly high-dose vitamin D did not significantly reduce major cardiovascular events in a largely vitamin D replete older population. A small protective signal for myocardial infarction warrants further study but does not justify supplementation for cardiovascular prevention in replete adults.
Limitations
Baseline 25(OH)D was not measured in most participants and the cohort was largely vitamin D sufficient, limiting ability to detect benefit in deficiency. Monthly bolus dosing may behave differently from daily dosing. Outcomes were derived from administrative data rather than adjudicated clinical review, and the trial was not powered as a primary cardiovascular trial.
Supplements Studied
Major cardiovascular events occurred in 6.0% of the vitamin D group versus 6.6% of placebo (HR 0.91, 95% CI 0.81-1.01) - a difference that did not reach statistical significance. Rates of myocardial infarction (HR 0.81) and coronary revascularisation (HR 0.89) were lower in the vitamin D group, while stroke rates were similar. Absolute risk difference was about 5.8 fewer events per 1,000 participants.
Study Details
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Disclosures
Funding
Australian National Health and Medical Research Council (NHMRC) project grants; investigator-initiated, no supplement industry funding
This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.