The authors identified individual randomized controlled trials from previous meta-analyses and additional searches, and then performed meta-analyses on cardiovascular disease outcomes and all-cause mortality. The authors assessed publications from 2012, both before and including the U.S. Preventive Service Task Force review. Their systematic reviews and meta-analyses showed generally moderate- or low-quality evidence for preventive benefits (folic acid for total cardiovascular disease, folic acid and B-vitamins for stroke), no effect (multivitamins, vitamins C, D, β-carotene, calcium, and selenium), or increased risk (antioxidant mixtures and niacin [with a statin] for all-cause mortality). Conclusive evidence for the benefit of any supplement across all dietary backgrounds (including deficiency and sufficiency) was not demonstrated; therefore, any benefits seen must be balanced against possible risks.
Jenkins, D. J. A., Spence, J. D., Giovannucci, E. L., Kim, Y. in, Josse, R., Vieth, R., … Sievenpiper, J. L. (2018, June 5). Supplemental Vitamins and Minerals for CVD Prevention and Treatment. Journal of the American College of Cardiology. Elsevier USA. https://doi.org/10.1016/j.jacc.2018.04.020