Research suggests a daily multivitamin may provide modest benefits for memory and cognitive function as people age.
Could something as simple as a daily multivitamin help protect the aging brain?
A growing body of research suggests it might. Studies from the large COcoa Supplement and Multivitamin Outcomes Study (COSMOS) have found that older adults taking a daily multivitamin performed modestly better on certain measures of memory and thinking than those taking a placebo.
The findings do not mean that multivitamins can prevent dementia or reverse memory loss. However, researchers say they add to evidence that adequate nutrition may play a role in maintaining cognitive health later in life.
What the Research Found
One of the largest studies examining the question involved 3,562 adults aged 60 and older. Participants were randomly assigned to take either a daily multivitamin/multimineral supplement or a placebo and completed online cognitive tests over three years.
The study, known as COSMOS-Web, focused particularly on episodic memory — the ability to remember information and experiences.
After one year, participants taking the multivitamin performed significantly better on a test of immediate recall than those taking the placebo. The benefit was also seen when researchers looked at memory performance across the full three years of follow-up.
Researchers estimated that the improvement was equivalent to approximately 3.1 years of age-related memory change.
That figure, however, needs some context. It does not mean that taking a multivitamin literally makes someone’s brain three years younger. Instead, the researchers used differences in test performance between age groups to estimate what the observed improvement might correspond to in terms of typical age-related changes.
The Improvement Was Modest
The results were encouraging, but the effects were not dramatic.
The multivitamin significantly improved immediate recall, but researchers did not find significant improvements in every cognitive ability they tested. Measures involving memory retention, executive function and novel object recognition did not show significant benefits in the COSMOS-Web study.
In other words, the findings suggest that a multivitamin may provide a small cognitive benefit, rather than acting as a powerful treatment for memory problems.
That distinction is important because memory changes can have many causes, including normal aging, sleep problems, medications, depression, nutritional deficiencies and neurological conditions.
More Than One Study Points in the Same Direction
The COSMOS-Web study was not an isolated finding.
A separate COSMOS clinical trial involving 573 adults aged 60 and older also found that daily multivitamin use was associated with more favourable changes in global cognition, memory and executive function compared with placebo. The study used detailed, in-person cognitive testing rather than online assessments.
Earlier, an NIH-supported trial involving more than 2,200 adults aged 65 and older reported improvements in global cognition, memory and executive function among participants taking a daily multivitamin compared with those taking a placebo. The effects were particularly noticeable among participants with a history of cardiovascular disease.
Together, these studies have strengthened interest in the potential relationship between multivitamin use and cognitive health.
Why Might a Multivitamin Affect the Brain?
The brain relies on a wide range of vitamins and minerals to function normally.
Nutrients such as vitamin B12, folate and vitamin D are involved in processes important to the nervous system, while other vitamins and minerals contribute to energy production, cell maintenance and normal brain function.
As people age, nutritional deficiencies can become more common because of changes in diet, appetite, absorption and medication use.
One possibility is therefore that multivitamins help by filling small nutritional gaps rather than by providing a specific “brain-boosting” ingredient.
Researchers have not yet established which individual nutrients, or combination of nutrients, are responsible for the cognitive effects observed in the studies. The COSMOS-Web researchers specifically noted that future research is needed to identify which nutrients may contribute to cognitive health.
It Is Not a Dementia Treatment
Despite the encouraging findings, scientists are not recommending multivitamins as a treatment for Alzheimer’s disease or dementia.
The studies measured changes in cognitive test performance. They were not designed to prove that multivitamins prevent Alzheimer’s disease or stop dementia from developing.
This distinction is especially important because a person can perform slightly better on a memory test without necessarily having a lower risk of developing dementia.
The NIH has also emphasized that more research is needed, particularly among more diverse populations, before firm conclusions can be drawn about the long-term effects of multivitamins on cognitive decline.
Who Took Part in the Studies?
The participants in the COSMOS-Web trial were generally healthy older adults rather than people with diagnosed Alzheimer’s disease or dementia.
The study also had limitations that researchers acknowledged. Participants needed access to the internet and sufficient computer skills to complete the cognitive assessments, and the study population was predominantly White and relatively highly educated.
That means the findings may not apply equally to every older adult population.
The type of supplement also matters. The COSMOS-Web study used Centrum Silver, so the results should not automatically be interpreted as proof that every multivitamin on the market will have the same effect.
What Should Older Adults Take From the Findings?
The research provides a reason to be interested in nutrition and brain health, but it is not a reason to rely on supplements alone.
A healthy diet, regular physical activity, adequate sleep and management of cardiovascular risk factors are all important parts of maintaining cognitive health as people age.
For someone who has a nutritional deficiency, taking the appropriate vitamin or mineral under medical guidance can be particularly important. But taking increasingly high doses of supplements is not necessarily better.
Anyone considering a multivitamin should also consider their existing medications, medical conditions and dietary needs and discuss supplementation with a healthcare professional when appropriate.
A Promising Piece of the Puzzle
The relationship between nutrition and brain health is complicated, and researchers are still trying to determine exactly why multivitamins appear to produce modest improvements in some aspects of cognition.
What makes the recent findings notable is the consistency across several large randomized clinical trials.
The evidence does not show that a multivitamin can make an older person’s brain dramatically sharper or prevent dementia. Instead, it suggests that something as ordinary as maintaining adequate intake of essential vitamins and minerals may offer a small benefit for certain aspects of memory and cognitive function.
For now, researchers are continuing to investigate which nutrients matter most and whether the benefits observed in cognitive tests translate into meaningful improvements in everyday life.
The answer may ultimately be less about finding a single “magic” vitamin and more about ensuring that the aging brain receives the nutrients it needs to function properly.
References
National Institutes of Health (NIH). “Daily multivitamin may enhance memory in older adults.” June 13, 2023.
Read the NIH report
Yeung, L. K. et al. “Multivitamin Supplementation Improves Memory in Older Adults: A Randomized Clinical Trial.” The American Journal of Clinical Nutrition, 2023.
Read the original research paper
The American Journal of Clinical Nutrition. “Multivitamin Supplementation Improves Memory in Older Adults: A Randomized Clinical Trial.”
Read the full study
National Institute on Aging (NIA). “Daily multivitamin may improve cognition in older adults.” October 5, 2022.
Read the NIA report
Baker, L. D. et al. “Effects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial.” Alzheimer’s & Dementia, 2022.
Read the research through NIH
COSMOS Research Program. The COcoa Supplement and Multivitamin Outcomes Study investigates the effects of multivitamins and cocoa flavanols on health outcomes in older adults.
Learn more about COSMOS research
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