Multivitamins: Worth It, or Expensive Urine?

Walk the vitamin aisle at any Hannaford in January and you will see the same quiet ritual. Carts pause. People squint at bottles, do a little mental math, and drop a multivitamin in next to the eggs. It feels responsible. It feels like cheap insurance against a long, dark Maine winter. But after a decade of large trials, the science has gotten specific about who that daily pill actually helps, and the answer is not what the marketing suggests.

First, the money

Americans buy a lot of vitamins. According to CDC data from the National Center for Health Statistics, 57.6% of US adults reported using a dietary supplement in the past 30 days, and multivitamin-mineral products were the single most popular type across every age group. Use climbs with age, from 24% of adults in their twenties and thirties up to 39.4% of those 60 and older.

That habit adds up. The US dietary supplement market runs to roughly $50 billion a year, with multivitamin sales alone around $8.3 billion in 2022. For a household watching its grocery bill, a daily multivitamin is a real recurring purchase, not pocket change. So it is fair to ask what you get for the money.

What the big trials found

Two recent studies carry most of the weight here, and both are large and well run.

The first is COSMOS, a randomized clinical trial of 21,442 older adults who took either a daily multivitamin-mineral or a placebo and were followed for a median of 3.6 years. Random assignment is the gold standard because it strips out the usual confounders. The result was flat. No significant reduction in total invasive cancer, no significant drop in cardiovascular disease, no meaningful change in the risk of dying. The pill performed about the same as the sugar tablet.

The second is even bigger. Researchers pooled three long-running cohorts totaling 390,124 healthy US adults, some tracked for up to 27 years, and compared daily multivitamin users with non-users. Published in JAMA Network Open in 2024, the analysis found no lower risk of death among the daily users. If anything there was a slight bump in apparent risk early on, which the authors chalk up to sick people starting supplements rather than the pills causing harm.

The US Preventive Services Task Force looked at this whole body of evidence and landed in the same place. In 2022 it concluded there is not enough evidence to recommend multivitamins to healthy adults for preventing heart disease or cancer. It went further on two specific ingredients, recommending against beta-carotene and vitamin E for that purpose.

A few real risks, mostly at high doses

More is not safer. The Task Force flagged that beta-carotene supplements raised the risk of lung cancer in smokers and people exposed to asbestos, and that vitamin E was tied to a higher risk of hemorrhagic stroke. Those are the harms behind the standing advice against blanket high-dose supplementing. A standard multivitamin is a low dose by design, but the lesson holds. Megadosing single nutrients on a hunch can backfire.

The one bright spot

Here is where it gets interesting. The same COSMOS trial that found nothing for cancer or heart disease did find something for the brain. In its cognitive substudies, a daily multivitamin beat placebo for memory and overall thinking. Researchers at Mass General Brigham estimated the effect was roughly equivalent to slowing cognitive aging by about two years over the course of the study.

That is a genuine finding from a serious trial, and it is the strongest case anyone has made for a daily multivitamin in healthy older adults. It deserves a real caveat too. The investigators themselves say it still needs to be confirmed by more research before anyone treats it as settled. Promising, not proven.

Who actually benefits

Multivitamins make the most sense when there is a real gap to fill. And gaps are more common than you might think. One US analysis estimated that 31% of the population is at risk of at least one vitamin deficiency or anemia, with higher rates among women (37%) and people in lower-income households (40%).

Age matters here. Adults 60 and older are at greater risk of vitamin D inadequacy, partly from eating less of it and partly from getting less sun. Pregnancy, certain medical conditions, restrictive diets, and some medications can all open a gap that a targeted supplement closes. The thread running through all of it is simple. Supplements are best at correcting a shortfall, not at adding a bonus on top of an already adequate diet.

What the label does not promise

One reason the aisle is confusing: there is no standard multivitamin. The NIH Office of Dietary Supplements notes that these products have no regulatory definition and vary widely from brand to brand. Two bottles labeled the same way can hold very different formulas.

And the FDA does not review supplements for effectiveness before they go on sale. Unlike prescription drugs, dietary supplements reach the shelf without an approval step. Manufacturers are responsible for their own safety claims, and the FDA usually steps in only after a product on the market turns out to be mislabeled or contaminated. The label tells you what the company says is inside. It is not a stamp of proof that the product works. For a plainer walkthrough of those panels, see our guide on how to read supplement labels.

The Maine angle

Geography is the part of this story that hits home. Maine sits between about 44 and 47 degrees north, well above Boston at roughly 42. That latitude has a measurable effect on what your skin can do. The classic Webb and Holick study found that human skin in Boston makes no previtamin D3 from sunlight between November and February, and that this vitamin D winter stretches longer the farther north you go. In Edmonton, Alberta, it ran from October through March. Maine falls in between, so our deficit window is longer than Boston’s.

That low-sun reality is a big reason so many Mainers reach for something off the shelf in winter. But it also points to a smarter buy. If the real shortfall is vitamin D, a single targeted vitamin D supplement maps onto the actual problem more cleanly than a broad multivitamin loaded with two dozen nutrients you may already get from food. Whether you need one, and how much, is a conversation for your own provider, who can check a level instead of guessing.

So, worth it?

For a healthy adult eating a reasonable diet, the evidence says a daily multivitamin is unlikely to make you live longer or dodge cancer and heart disease. Most of the extra you swallow does leave in your urine, so the old “expensive urine” jab is not entirely a joke. The exceptions are real and worth knowing. Older adults thinking about memory, anyone with a documented deficiency, and people in higher-risk groups have a better case. For everyone else in the checkout line, the honest answer is that a targeted nutrient, chosen with a provider’s input, usually beats a catch-all pill.

Sources

• CDC / National Center for Health Statistics. Dietary Supplement Use Among Adults: United States, 2017-2018 (NCHS Data Brief No. 399). 2021. https://www.cdc.gov/nchs/products/databriefs/db399.htm
• HealthExec. As Americans tuck into supplements, specialized products are displacing multivitamins. 2024. https://healthexec.com/topics/healthcare-management/business-intelligence/americans-dietary-supplements-multivitamins
• NIH Office of Dietary Supplements. Multivitamin/Mineral Supplements – Health Professional Fact Sheet. 2024. https://ods.od.nih.gov/factsheets/MVMS-HealthProfessional/
• American Journal of Clinical Nutrition (PMC). COSMOS randomized clinical trial (cancer and cardiovascular disease). 2022. https://pmc.ncbi.nlm.nih.gov/articles/PMC9170475/
• JAMA Network Open. Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts. 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11208972/
• National Institutes of Health. For healthy adults, taking multivitamins daily is not associated with a lower risk of death. 2024. https://www.nih.gov/news-events/news-releases/healthy-adults-taking-multivitamins-daily-not-associated-lower-risk-death
• U.S. Preventive Services Task Force. Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer. 2022. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/vitamin-supplementation-to-prevent-cvd-and-cancer-preventive-medication
• Mass General Brigham. Third Major Study Finds Daily Multivitamin Supplements Improve Memory and Slow Cognitive Aging in Older Adults. 2023. https://www.massgeneralbrigham.org/en/about/newsroom/press-releases/multivitamins-improve-memory-and-slow-cognitive-aging
• American Journal of Clinical Nutrition. Effect of multivitamin-mineral supplementation versus placebo on cognitive function (COSMOS clinic subcohort and meta-analysis). 2023. https://ajcn.nutrition.org/article/S0002-9165(23)66342-7/fulltext
• EurekAlert! (AAAS). Study finds daily multivitamin supplements improved memory and slowed cognitive aging in older adults. 2023. https://www.eurekalert.org/news-releases/990005
• Nutrients (PMC). The Prevalence and Determinants of Vitamin D Inadequacy among U.S. Older Adults: NHANES 2007-2014. 2019. https://pmc.ncbi.nlm.nih.gov/articles/PMC6768617/
• Nutrients (PMC). Risk of Deficiency in Multiple Concurrent Micronutrients in Children and Adults in the United States. 2017. https://pmc.ncbi.nlm.nih.gov/articles/PMC5537775/
• U.S. Food and Drug Administration. Questions and Answers on Dietary Supplements. 2022. https://www.fda.gov/food/information-consumers-using-dietary-supplements/questions-and-answers-dietary-supplements
• Journal of Clinical Endocrinology & Metabolism (PubMed). Influence of season and latitude on the cutaneous synthesis of vitamin D3 (Webb/Holick). 1988. https://pubmed.ncbi.nlm.nih.gov/2839537/

This article is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before making any health decisions.