Effie Viguiliouk, Atherai Maran, Darshna Patel, Awad Chowdhury, Taylor McKay, Edward Giovannucci, Anisa Hajizadeh, Sandy Mitchell, Amy E. Jenkins, Ramsha Shahid, Sandhya Sahye-Pudaruth, David J.A. Jenkins, Tina Qutta, Sathish C. Pichika, Stephanie K. Nishi, Julieta Correa-Betanzo, Cleo Villegas, Robert G. Josse, Gabriella Del Principe, Daniel Bernstein, Ruben Kalaichandran, Narmada Umatheva, John L. Sievenpiper, Gelaine Trinidad, Sonia Blanco Mejia, Lina Bachiri, Geithayini Kirupaharan, Rohit Jayaraman, Meaghan Kavanagh, Young-In Kim, Cyril W. C. Kendall, Tom Tsirakis, Wendy M. Jenkins, Alexis Silver, Jessica White, Reinhold Vieth, Melanie Paquette, Preveena Manisekaran, and J. David Spence
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.