A daily multivitamin is one of the most common supplements in the US, and it is also one of the least understood at the molecular level. A new analysis from the COSMOS randomized trial looked at what two years of Centrum Silver did to the blood metabolome of older adults. It found a few interesting shifts, along with a major caveat that headlines tend to skip.
The study, led by Li and colleagues, was published in GeroScience (DOI: 10.1007/s11357-026-02197-9; PubMed).
The Setup: What Was Tested
COSMOS (COcoa Supplement and Multivitamin Outcomes Study) is a 2 × 2 factorial, placebo-controlled, double-blinded randomized trial in US older adults. This analysis focused on the multivitamin-multimineral (MVM) arm, using Centrum Silver® versus placebo.
The metabolomics subset included 399 participants (average age 70.3 ± 5.7 years; 50.1% female). Blood samples were profiled on the Nightingale Health NMR platform at baseline, year 1 and year 2. The researchers examined:
- 168 individual metabolites
- 7 metabolomic clocks of biological aging
- 24 metabolomic risk scores (MRS) for chronic diseases
The Metabolites That Moved
Compared with placebo, two years of daily MVM:
- Increased docosahexaenoic acid (DHA). Cohen's d was 0.212 (95% CI, 0.02 to 0.404).
- Increased total omega-3 fatty acids. Cohen's d was 0.193 (0.003 to 0.382).
- Delayed the rise in creatinine. Cohen's d was -0.222 (-0.424 to -0.019).
These are small effect sizes, and the confidence intervals sit close to zero. Creatinine is often used as a marker of kidney function, but the abstract does not interpret the finding in clinical terms. It reports only that the usual rise over time was blunted in the MVM group.
The Disease-Risk Scores
MVM also lowered metabolomic risk scores for 16 chronic diseases, with Cohen's d ranging from -0.206 to -0.277. The conditions named in the abstract include:
- Major cardiovascular events
- Renal disease
- All-cause dementia
- Asthma
- Cataracts
- Glaucoma
- Liver disease
- Non-melanoma skin cancer
- Prostate cancer
These scores are statistical estimates built from metabolite patterns. They are not diagnoses and not actual disease outcomes, so a lower score does not mean anyone in the trial avoided one of these diseases.
The Aging Clocks: A Nudge, Not a Reversal
The most tempting headline is that the multivitamin turned back biological age. The data do not support that. MVM produced a non-significant decrease across all seven metabolomic aging clocks, ranging from 0.496 to 1.054 years. The direction was consistent, but the result was not statistically significant.
The Catch You Can't Ignore
Every effect above was significant only at the nominal level (p < 0.05). None survived correction for multiple testing (FDR > 0.05). When you test 168 metabolites, 7 clocks and 24 risk scores, some will look significant by chance alone. The authors call the results preliminary evidence that daily MVM "may modestly improve metabolomic profiles in older adults," and note the limited sample size.
The abstract also doesn't say whether these metabolic shifts lead to better health. The authors state that further work within COSMOS is needed to confirm whether these changes contribute to the benefits of MVM supplementation for healthy aging.
Practical Takeaways
Dose: The trial used a daily Centrum Silver multivitamin-multimineral, a once-a-day product designed for older adults. The abstract does not give the exact formulation or tablet count, so check the label or the full paper.
Timing: The abstract says nothing about the best time of day or whether to take it with food. Nothing here supports a specific timing strategy. The only timing evidence is that the effects were measured over 1 and 2 years of consistent daily use.
Who it may be relevant to: The participants were older US adults averaging 70 years old. The findings apply most directly to that group, not to younger people or those with different baseline nutrition.
Who should be cautious or skip it:
- Anyone hoping for a proven anti-aging effect. The aging-clock changes were not statistically significant.
- Anyone expecting disease prevention. This study measured blood-based risk scores, not disease events.
- People with kidney disease, those on prescription medications, or those on other supplements. This is general precaution, not a finding of this paper. Talk to a clinician first, especially since creatinine changes were among the results.
Bottom line: Two years of a standard multivitamin was associated with modest, directionally favorable shifts in DHA, omega-3s, creatinine trajectory and disease-risk scores. These are hypothesis-generating signals, not proof. A multivitamin is not a verified longevity tool on this evidence alone, and larger follow-up analyses will show whether the signals hold up.
Source: Li et al., GeroScience, 2-year findings from the COSMOS randomized clinical trial. Trial registration: NCT02422745.
