What did the COSMOS trials use for multivitamin composition and which populations were studied?
Executive summary
The COSMOS trials tested a commercially available multivitamin-mineral (MVM) formulation—reported by the study team as Centrum Silver® (or a formulation very similar to Centrum Silver® Adults 50+)—within a large, randomized, double-blind, placebo‑controlled 2×2 factorial study also testing cocoa flavanols (500 mg/d) [1] [2] [3]. The population was older U.S. adults: roughly 21,442 participants in the parent trial (about 12,666 women ≥65 y and 8,776 men ≥60 y), with cognitive ancillary studies drawing on thousands more focused older-adult participants including COSMOS-Clinic (n = 573), COSMOS‑Mind (n ~2,158), and COSMOS‑Web (n ~2,472) [3] [4] [5] [6].
1. The multivitamin identity and how the investigators describe its composition
COSMOS investigators explicitly state that the multivitamin tested was a commercial multivitamin-mineral product described as Centrum Silver® or a multivitamin “very similar” to the Centrum Silver® Adults 50+ formulation used in the marketplace, and they caution readers about generalizing beyond similar multivitamin products [1] [2]. The trial protocol and design papers likewise refer to a “standard multivitamin (Centrum Silver®)” as the MVM arm of the trial, framing COSMOS as a pragmatic test of a widely used, broad-spectrum multivitamin rather than a bespoke high-dose nutrient cocktail [2].
2. What the trial literature does and does not disclose about ingredients
Public-facing COSMOS materials and the protocol identify the product by brand similarity but do not provide a full ingredient table or per‑dose micronutrient breakdown in the sources supplied here; investigators therefore anchor the description to the commercial product rather than reproducing the full composition in the main trial documents available online [1] [2]. Because the multivitamin was a retail product (Centrum Silver® Adults 50+), detailed composition can be obtained from the manufacturer’s label, but that full ingredient list is not reproduced in the COSMOS source excerpts provided for this briefing [1].
3. Who was enrolled in the parent trial and what subpopulations were studied for cognition
The COSMOS parent trial randomized about 21,442 U.S. adults to the factorial interventions, specifically recruiting older women and men—roughly 12,666 women aged ≥65 years and 8,776 men aged ≥60 years—with a median of about 3.6 years of treatment and follow-up [3] [4]. Cognitive effects were examined through three nonoverlapping ancillary cognitive studies: COSMOS‑Clinic (in‑person neuropsychological testing, n = 573), COSMOS‑Mind (telephone-assessed cognition, ~2,158 participants), and COSMOS‑Web (web-based cognitive testing, ~2,472 participants); the authors meta-analyzed nonoverlapping participants across those substudies to evaluate MVM effects on cognition [5] [6].
4. What outcomes were targeted and how population framing shaped interpretation
COSMOS was structured as a pragmatic prevention trial with co-primary foci: the cocoa extract intervention targeted cardiovascular endpoints while the multivitamin arm had total invasive cancer as its primary outcome in the full cohort, reflecting prior signals from earlier trials of multivitamins in men and the need for confirmatory evidence in women and mixed cohorts [2] [3]. Cognitive ancillary studies repurposed the randomized exposure to test whether a daily MVM could slow cognitive aging in generally healthy older adults, and several COSMOS cognitive reports concluded that MVM use was associated with modest improvements in global cognition, episodic memory, and executive function across the substudies and meta-analyses [7] [6].
5. Conflicts, funding and interpretive cautions
COSMOS was a large collaboration involving academic investigators and industry partners—NIH funding plus support noted from industry stakeholders in publicly available ancillary materials—and industry relationships are disclosed in related summaries, which is pertinent when the tested MVM is a branded, market-available product [8]. The available reports emphasize that findings apply to the tested commercial MVM (Centrum Silver® or a very similar formula) among generally healthy U.S. older adults and that extrapolating to different formulations, doses, younger populations, or people with established nutrient deficiencies would exceed the evidence presented in these sources [1] [2] [6].