You’re late, with no time to chop fruit or rinse lettuce before driving to work. In your race out the door, you pitstop at the pantry for a protein bar or toaster pastry. Not exactly textbook nutrition, but it’s okay, you remind yourself. Earlier, you took a multivitamin.
That multivitamin may seem like armor against a hasty, nutrient-sparse breakfast. About one-third of adults take them, and many doctors recommend them for some children and other specific groups.
But several recent studies have found that multivitamins don’t actually improve health outcomes—with a few exceptions—and pills with too much “nutrition” might even backfire. Here’s what to know about multivitamins: when they’ll likely help, harm, or do absolutely nothing.
Multivitamins vs. nutrition
A daily multivitamin probably won’t be your savior. The bedrocks of healthy behavior are your biggest assets for staying disease-free. “Diet, exercise, and other healthy lifestyle habits matter the most,” says Howard Sesso, associate professor of epidemiology at Brigham and Women’s Hospital and Harvard Medical School, who has studied people’s health outcomes when they take multivitamins.
So-called “broad-based” multivitamins combine a wide range of micronutrients, with typically around 13 essential vitamins like A, C, and D, and up to 15 minerals like calcium, magnesium, and zinc. Other multivitamins focus on fewer nutrients for specific needs like bone or skin health.
But humans evolved to get their nutrition from real food, which has major advantages over pills. For one thing, food packages nutrition with fats, enhancing absorption. Many healthy foods also contain complex antioxidants like polyphenols, which help preserve vitamins inside the body as they work their good deeds. Pills can pack polyphenols, too, but shelf-life and bioavailability depend on the type of polyphenol and what else is mixed in.
Read More: How to Keep Your Heart Healthy in Your 20s, 30s, 40s, and Beyond
“Following a balanced dietary pattern is the key for most adults to obtain their essential micronutrients to foster healthy development, disease prevention, and overall wellness,” says Stephanie Lopez-Neyman, a dietitian and assistant professor of nutrition at the University of Arkansas for Medical Sciences.
Research showing clear benefits of multivitamins is scant. In 2022, the U.S. Preventive Services Task Force concluded there isn’t enough evidence to justify recommending their use for disease prevention among healthy people who don’t have any special nutrient requirements.
When Sesso studied male physicians taking daily multivitamins for more than a decade through a large, carefully controlled trial, he found they didn’t help with fending off heart disease or earlier death, but they were linked to some reductions in cancer and cataracts.
Last year, NIH researchers found that regular multivitamins didn’t improve longevity across nearly 400,000 healthy adults. However, the researchers noted that a handful of other studies have shown certain benefits, and more research is needed to understand how these pills affect specific groups of people.
Who might benefit?
One such group is seniors. “We know that some nutritional deficiencies are more likely to develop in older people,” Sesso says. The most frequent examples are vitamin B12 and vitamin D.
In a 2024 trial of about 5,000 older adults, Sesso and colleagues found that multivitamin use led to enhanced memory and delayed cognitive aging by two years. Broad-based multivitamins contain essential vitamins and minerals that “target multiple biological pathways to support cognitive health,” Sesso and his co-authors wrote.
In the same trial but with an even bigger group of seniors, multivitamin-takers were also less likely to get lung cancer, but no benefits were observed for other cancers or heart disease. Some of Sesso’s research—including this trial—receives company funding, but he designs the studies without company input. He now plans to investigate how these findings might apply to younger people.
Read More: 11 Symptoms Foot Doctors Say You Should Never Ignore
Another group that may benefit are people with nutritional deficiencies, though such deficiencies aren’t common in the U.S., Sesso explains. They’re more likely among those with low-calorie diets, poor appetite due to chronic illness, or little access to healthy food. Food-insecure adults may have better health outcomes when they’re taking multivitamins.
Strict vegetarians or vegans may miss out on certain vitamins and minerals. For them, “taking a multivitamin could be advantageous,” Lopez-Neyman says. She adds that multivitamins can also help pregnant women. They’re advised to take multivitamins due to a higher risk of deficiencies in nutrients such as folate and iron.
Multivitamins could be useful during periods of chronic stress and sleep deprivation, such as rough stretches at work or school. These circumstances may interfere with cooking nutritious meals, and stress can sap immunity. Multivitamins could, in theory, help with both issues. “If you’ve been struggling to eat a varied diet for six months or longer, it’s a good time to check in with your doctor or dietitian,” says Raedeh Basiri, assistant professor of nutrition and food studies at George Mason University.
Multivitamins and kids
Pediatricians may recommend multivitamins for kids because their bodies are continuously developing, “requiring a steady supply of essential nutrients to support physical and mental milestones,” Lopez-Neyman says.
She adds, though, that the American Academy of Pediatricians doesn’t advise multivitamins for children who eat reasonably well. That’s largely because packaged foods fortified with vitamins and minerals boost their micronutrient intake. “Their bodies should learn how to get what they need from food,” Basiri says. “That has been the case for thousands of years.”
Exceptions are vitamin D, especially for infants, and a few minerals like iron and calcium. Both children and adults of all ages have some risk of not getting enough of these critical nutrients.
Specialized multivitamins
Talk with doctors or dietitians to learn more. They can order tests to uncover any deficiencies, in which case a broad-based multivitamin may help. They might also recommend a specialized multivitamin with only the nutrients that target a particular shortage, in addition to dietary changes.
A common specialized multivitamin offers B12, which can be low especially among vegetarians. Lopez-Neyman rarely has meat, and her provider suggested a multivitamin with B12, B6, and folate.
Read More: Weighted Vests Are the Latest Fitness Trend. Do They Work?
Compelling evidence shows that multivitamins combining beta carotene, vitamins C and E, copper, and zinc delay progression of macular degeneration after the condition has been diagnosed.
Risks of multivitamins
Many of us grew up striving for 100% on every test, but overachieving with multivitamins comes with risk—diminishing their benefits or causing harmful side effects. Whether taking a broad-based or specialized multivitamin, talk to your doctor or dietitian about your individual nutrition needs. You might not always want a pill that provides the recommended daily allowance for each vitamin and mineral.
“We wouldn’t want 100% of everything,” says Christy Bock, a pediatric dietitian in Washington, DC. Even at lower percentages, many nutrients amplify each other, collaborating inside the body to potentially provide 100% of your needs. “Nature works together in certain patterns,” Bock says. “It’s the same with vitamins and nutrients in food.”
Bock adds that too much of certain nutrients may undermine others. For example, getting more than 100% of calcium daily could interfere with the beneficial effects of iron, she says.
Read More: Can Creatine Keep Your Brain Sharp?
Excess nutrients can build up over time to become toxic. In particular, vitamins that dissolve in fat—like A, D, E, and K—accumulate in the body’s tissues, increasing the chances they’ll reach toxic levels, Bock explains. High doses of vitamin E, for instance—say 1,200 milligrams—can lead to side effects like diarrhea, weakness, or blurred vision, Lopez-Neyman says.
Parents should be cautious about gummies that have artificial additives and tempt kids to eat them like candy, leading to the risk of overdose, Basiri says.
How to decide whether to take a multivitamin
Many of us reach for multivitamins because we feel too rushed to prepare healthy food. But doctors and dietitians can help you revisit this assumption. Batch cooking and portable healthy snacks ensure plenty of nutrients while reducing time pressure, Basiri says.
If you still want a broad spectrum multivitamin, look for ones certified by NSF, USP, or ConsumerLab.com—or at least use an established, familiar brand.
Whether to take a multivitamin could come down to personal preference. Based on his own research, Sesso started taking multivitamins daily after he turned 50, on top of eating healthy. “Lifestyle is the first line of defense,” he says. He always takes the multivitamin with food, since the body recognizes and uses it better that way, he says.
Others may want to carefully consider if a multivitamin is really delivering the best benefit for their situation. Logging more hours of sleep, for instance, would boost health more than any pill for the majority of people. “What variable in your life is most important to identify?” Bock says. “A multivitamin can be helpful in some circumstances, but it’s not always the answer.”
The post Can a Multivitamin Make Up for a Bad Diet? appeared first on TIME.
