Researchers from the Georgia Prevention Institute at Augusta University analyzed data from the COcoa Supplement Multivitamins Outcomes Study (COSMOS), in which adults 60 and older were randomized to a daily multivitamin, a cocoa extract, both, or placebo. After three years, the multivitamin group reported significantly better functional health — measured with the Kansas City Cardiomyopathy Questionnaire — than the placebo group, with the strongest differences in symptom burden and the clinical summary score. The cocoa extract showed no significant overall effect, though it was associated with a benefit among participants with congestive heart failure.
Three limits belong in the reading. The results are preliminary — abstracts at NUTRITION 2026 were committee-selected but have not completed journal peer review. The measure is self-reported functional health, not disease outcomes. And the researchers themselves were explicit that the multivitamin "is not a substitute for a good diet or exercise." The practical takeaway is a modest one: for older adults, a daily multivitamin was associated with better reported daily function — and anyone considering a new supplement should talk with a clinician first.
For stone patients, the supplement conversation has a kidney-specific layer the multivitamin study does not cover. The stone-relevant nutrients in a multivitamin are calcium, vitamin D, and vitamin C — and all three carry a measured note for stone formers. Calcium supplements, especially calcium carbonate taken without food, can raise urinary calcium; dietary calcium at meals remains the stone-protective route. Vitamin D, which the body needs to use calcium, is the clinical question with a stone history. And high-dose vitamin C is metabolized to oxalate, which matters for calcium-oxalate stone formers. The measured version of the multivitamin question is the care-team version: the stone history on the chart, the 24-hour urine numbers if available, and the supplement chosen or skipped on those numbers rather than on a headline.
The study's own disclaimer — the supplement is not a substitute for diet — is the stone plan's oldest rule in different words: the dairy at meals, the water on schedule, and the measured portions carry the plan, and the supplement shelf is the measured addition, not the foundation. The table below shows the measured values of the foods that remain the base of the older adult's stone plan.
| Food | Oxalate (mg) | Serving | Rating |
|---|---|---|---|
| Milk, cow's | 0 | 1 cup | Safe |
| Greek yogurt, plain | 0 | 1 cup | Safe |
| Cottage cheese | 0 | 1/2 cup | Safe |
| Eggs, hard-boiled | 0 | 2 large | Safe |
| Salmon, baked | 0 | 4 oz | Safe |
| Oatmeal, cooked | 9 | 1/2 cup | Safe |
| Bananas | 6 | 1 medium | Safe |
| Broccoli, boiled | 4 | 1/2 cup | Safe |
The COSMOS analysis linked a daily multivitamin to better reported functional health in older adults, but it is not a stone-specific finding and the results are preliminary. The supplement decision should go through the care team with the stone history on the chart — especially the calcium, vitamin D, and vitamin C contents, which carry stone-relevant notes.
High-dose vitamin C is metabolized to oxalate, which matters for calcium-oxalate stone formers. Standard multivitamin doses are generally modest, but the high-dose single supplements are the ones to discuss with the care team. The stone history should be part of the supplement conversation.
The plate: dairy at meals for calcium, water on schedule, and measured portions — the study's own disclaimer called the supplement "not a substitute for a good diet or exercise." The supplement shelf is the measured addition, chosen with the clinician, not the foundation.
The measured supplement conversation reads the label and brings the history. The label columns that matter for stone formers are the calcium, vitamin D, and vitamin C lines — the three nutrients in a multivitamin that carry stone-relevant notes — and the daily totals, because the supplement sits on top of the dietary calcium, not instead of it. The history is the other half: a stone former bringing the 24-hour urine numbers or the stone analysis to the supplement conversation gives the clinician the numbers that make the decision, rather than leaving it to a headline or a habit. The measured version of the multivitamin question is not "should I take one" in the abstract; it is "with my numbers and my history, what belongs on my supplement shelf" — a conversation, not a purchase.
The study itself models the right posture: preliminary results, modest claims, and an explicit reminder that the supplement is not a substitute for diet and exercise. The stone plan has the same posture toward the supplement shelf — the plate first, the supplement as the measured addition, and the clinician in the loop.
See how oxalate values are measured and verified on our data methodology page.