Do you take a daily multivitamin? If recent surveys are to be believed, the answer is likely yes – nearly three out of every five US adults reported using some kind of dietary supplement in 2021, and the market in North America is worth around $50 billion a year at the most recent estimates.
That’s an awful lot of money to spend on something that may not actually do much – but according to a new editorial, written by scientists at Northwestern University and published this week in JAMA, that’s exactly what we’re all doing.
“If [multivitamins] were really good for you, we'd know by now,” said co-author Jeffrey Linder, chief of general internal medicine in the department of medicine at Northwestern University Feinberg School of Medicine, in a statement.
The editorial comes in support of new recommendations from the United States Preventive Services Task Force (USPSTF), which recently performed a meta-review of 84 studies into the effectiveness of dietary supplements. Their conclusion: there’s “insufficient evidence” that taking multivitamins, paired supplements or single supplements can help prevent cardiovascular disease and cancer in otherwise healthy, non-pregnant adults.
That last caveat is important: “Pregnant individuals should keep in mind that these guidelines don't apply to them,” cautioned co-author Natalie Cameron, a Northwestern Medicine physician and instructor of general internal medicine at Feinberg.
“Certain vitamins, such as folic acid, are essential for pregnant women to support healthy fetal development. The most common way to meet these needs is to take a prenatal vitamin,” Cameron said. “More data is needed to understand how specific vitamin supplementation may modify risk of adverse pregnancy outcomes and cardiovascular complications during pregnancy.”
Now, sure, you may be thinking, perhaps there is no real evidence that vitamins do much – but they can’t hurt, right? Let the people have their maybe tiny vitamin boost followed by a very expensive pee!
But according to the Northwestern doctors, it’s not that simple.
“Patients ask all the time, ’What supplements should I be taking?’,” said Linder. “They're wasting money and focus thinking there has to be a magic set of pills that will keep them healthy when we should all be following the evidence-based practices of eating healthy and exercising.”
Of course, "that’s easier said than done, especially among lower-income Americans,” said co-author Jenny Jia, who studies the prevention of chronic diseases in low-income families through lifestyle interventions.
“Healthy food is expensive, and people don't always have the means to find environments to exercise,” she explained. “Maybe it's unsafe outdoors or they can't afford a facility.”
But if you can eat healthily and exercise regularly, it’s worth it: while multivitamins and other supplements often boast that they contain everything a healthy body needs, the team points out that whole fruits and vegetables contain those same nutrients and much more – vitamins, fiber, phytochemicals, all likely acting together in a way that simply can’t be reproduced in pill form.
“The task force is not saying ‘don't take multivitamins,’” Linder explained, “but […] the harm is that talking with patients about supplements during the very limited time we get to see them, we're missing out on counseling about how to really reduce cardiovascular risks, like through exercise or smoking cessation.”