Am J Clin Nutr. 2026 Jun 9;124(1):101355. doi: 10.1016/j.ajcnut.2026.101355. Online ahead of print.
ABSTRACT
BACKGROUND: The effect of long-term daily multivitamin-mineral (MVM) supplementation on Coronavirus Disease 2019 (COVID-19) prevention and symptom severity remains unclear.
OBJECTIVES: We tested the hypothesis that a daily MVM reduced COVID-19 incidence or symptom severity among generally healthy older adults.
METHODS: We conducted a secondary analysis in the COcoa Supplement and Multivitamin Outcomes Study, a randomized, double-blinded, placebo-controlled trial (June 2015 to December 2020), evaluating daily MVM and cocoa extract supplementation for the prevention of cardiovascular disease and cancer among 21,442 United States adults. The primary outcome was incident COVID-19 between 1 January, 2020 and 31 December, 2020, defined as the first occurrence of a self-reported positive test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, a physician's diagnosis, hospitalization, or death due to COVID-19. The prespecified secondary outcomes were symptomatic COVID-19 and symptom count among nonfatal cases through 31 August, 2020, when detailed symptoms were collected. We conducted intention-to-treat (primary) and per-protocol (secondary) analyses among consistently adherent participants.
RESULTS: The final year of the COcoa Supplement and Multivitamin Outcomes Study intervention phase from January 2020 to December 2020 coincided with the start of the COVID-19 pandemic. Of the 18,205 participants who remained in the trial and were adherent to study pills as of 1 January, 2020, 382 were randomly assigned to MVM and 404 to MVM placebo (no MVM) and reported a COVID-19 infection through 31 December, 2020. In intention-to-treat analysis, the hazard ratio for MVM compared with placebo was 0.93 for COVID-19 incidence [95% confidence interval (CI): 0.81, 1.07]. Among the 338 cases with detailed symptom data, the odds ratio for symptomatic COVID-19 comparing MVM with placebo was 0.70 (95% CI: 0.44, 1.11). In per-protocol analyses, among participants compliant with study pills during 2020, the odds ratio for symptomatic COVID-19 was 0.60 (95% CI: 0.37, 0.99).
CONCLUSIONS: A daily MVM supplement, compared with placebo, does not significantly reduce COVID-19 incidence among older adults but shows a promising signal lowering the odds of symptomatic COVID-19 illness. The Cocoa Supplement and Multivitamin Outcomes Study was registered at clinicaltrials.gov as NCT02422745.
PMID:42385272 | DOI:10.1016/j.ajcnut.2026.101355