Association of multivitamin and mineral supplementation and risk of cardiovascular disease: A systematic review and meta-analysis

Background: Multiple studies have attempted to identify the association between multivitamin/mineral (MVM) supplementation and cardiovascular disease (CVD) outcomes, but the benefits remain controversial. We performed a systematic review and meta-analysis of the associations between MVM supplementation and various CVD outcomes, including coronary heart disease (CHD) and stroke. Methods and Results: We conducted a comprehensive search of Medline, Embase, and the Cochrane Library for studies published between January 1970 and August 2016. We included clinical trials and prospective cohort studies in the general population evaluating associations between MVM supplementation and CVD outcomes. Data extraction and quality assessment were independently conducted by 2 authors, and a third author resolved discrepancies. Eighteen studies with 2 019 862 participants and 18 363 326 person-years of follow-up were included in the analysis. Five studies specified the dose/type of MVM supplement and the rest did not. Overall, there was no association between MVM supplementation and CVD mortality (relative risk [RR], 1.00; 95% confidence interval [CI], 0.97-1.04), CHD mortality (RR, 1.02; 95% CI, 0.92-1.13), stroke mortality (RR, 0.95; 95% CI, 0.82-1.09), or stroke incidence (RR, 0.98; 95% CI, 0.91-1.05). There was no association between MVM supplements and CVD or CHD mortality in prespecified subgroups categorized by mean follow-up period, mean age, period of MVM use, sex, type of population, exclusion of patients with history of CHD, and adjustment for diet, adjustment for smoking, adjustment for physical activity, and study site. In contrast, MVM use did seem to be associated with a lower risk of CHD incidence (RR, 0.88; 95% CI, 0.79-0.97). However, this association did not remain significant in the pooled subgroup analysis of randomized controlled trials (RR, 0.97; 95% CI, 0.80-1.19). Conclusions: Our meta-analysis of clinical trials and prospective cohort studies demonstrates that MVM supplementation does not improve cardiovascular outcomes in the general population.