Do Multivitamins Actually Do Anything?
By: Houston Methodist The Woodlands Hospital | Published 10/17/2022
When considering ways to stay healthy, a multivitamin may seem like a sensible, easy choice.
But do multivitamins really provide health and wellness benefits or are they just empty promises and expensive urine?
What is a multivitamin?
There's no standardization around what exactly you can expect to find (or how much of it) in the multivitamins available, but generally speaking these supplements are formulated to help you meet the recommended dietary allowance for many of the vitamins and minerals your body needs to function optimally.
Which is why many people take a multivitamin.
The labels certainly advertise a number of desirable health outcomes: improved bone health, immune support and energy boost, just to name a few.
The reality, though, is that a healthy diet brings those same benefits, all a person needs to meet their body's vitamin and mineral requirements.
Should you take a multivitamin every day?
"Rather than taking a multivitamin, the goal really should be to get all of the vitamins and minerals we need from the foods we eat, through well-balanced meals," says Dr. Lola Okunnu, a primary-care doctor at Houston Methodist.
We all know what the average American diet looks like, though. Specifically, we know what it lacks — fruits, vegetables and whole grains, three of the cornerstones of a well-balanced diet.
So does that mean you should take a multivitamin every day to stay healthy?
Dr. Okunnu says, "On average, I would say no. Well, yes and no."
To appreciate the uncertainty in her answer, it helps to understand what we know (and don't know) about the benefits of multivitamins, their safety and when they might be worth it.
Do multivitamins work?
Dr. Okunnu poses a question, "For the average person who isn't actually deficient, does giving yourself more of these vitamins and minerals than you need actually benefit your overall health?"
Her answer: Probably not.
"The supposed benefits of multivitamins for otherwise healthy people aren't backed by evidence," says Dr. Okunnu.
In fact, the opposite is true in some cases. A 2021 review conducted by the U.S. Preventive Services Task Force analyzing the results of 84 vitamin and mineral supplement trials determined that taking a multivitamin provides little to no benefit in preventing heart disease and cancer, for instance.
Whether multivitamins have any impact on other wellness claims — improved energy levels, immunity, bone health, metabolism — remains unproven.
And if you are found to be deficient in a specific vitamin or mineral — such as vitamin D or iron — your doctor likely will recommend taking a single supplement rather than a multivitamin.
Multivitamins may, however, be beneficial for certain people, including those who:
- Have a health condition that causes malabsorption
- Take a medication that affects vitamin or mineral absorption
- Have had weight loss surgery
- Eat a vegan diet
- Have a poor diet — low vegetable intake, in particular
"These are things that can put you at risk for developing a nutrient deficiency," explains Dr. Okunnu, "Your doctor may recommend taking a multivitamin to help reduce that risk."
So...are multivitamins worth it?
The benefits of multivitamins are limited for otherwise healthy people.
But the value of taking a multivitamin — to you, specifically — may depend on your wallet or desire for better peace of mind.
"If you're eating well-rounded meals three times a day, the only thing a multivitamin provides you is expensive urine," says Dr. Okunnu.
These nutrients are indeed important, but your body can only absorb so much of them. It's the job of your kidneys to help remove the excess.
If you're worried about the quality of your diet, you might look at a multivitamin like an insurance policy, though — worth the assurance that your vitamin and mineral needs are covered.
The good news is that, even when all they're producing is expensive urine, what they won't cost you is your health, says Dr. Okunnu.
"Taking a reputable multivitamin every day is unlikely to harm you," says Dr. Okunnu.
She stresses, though, that they shouldn't be viewed as a pass to eating poorly — since a healthy diet comes with numerous other benefits, including satiety and meeting your daily fiber intake.
Dr. Okunnu also adds that some multivitamins are better than others. And if they're formulated incorrectly, they can even be unsafe.
"Multivitamins aren't regulated by the FDA, so be very careful about the brand of multivitamin you purchase," Dr. Okunnu warns.
What's the best multivitamin to take?
Just because a multivitamin looks fancy or is promoted by someone you follow on social media doesn't mean it's the best choice.
"The most important thing about taking a multivitamin is that, since they're not regulated by the FDA, the need to do your own research before deciding which is right for you," says Dr. Okunnu.
To be sure you're getting a quality product, it's essential that you verify your multivitamin has undergone testing and been certified by an independent, third-party laboratory, such as NSF or U.S. Pharmacopeia (USP). ConsumerLab.com also offers online reports of independent testing and evaluation of many vitamins and supplements, including multivitamins.
"These services not only confirm the product contains the ingredients listed on the label, but also that those ingredients are present in the amounts listed," adds Dr. Okunnu. "This is important since an untested supplement could contain more than what's listed on the label or even unknown, potentially harmful additives."
As for which multivitamin form is best — capsules, tablets, gummies or liquids — Dr. Okunnu says there's really no difference.
"Choose what works for you," Dr. Okunnu recommends. "The focus with multivitamins really needs to be finding one that is produced by a reputable source and has been third-party tested."
It's also advised that you to choose a vitamin formulated for your age and sex — since women, children and the elderly may need more or less of certain vitamins and minerals, as well as different ones, than other groups of people.
Are there side effects of multivitamins you should be aware of?
As mentioned, multivitamins are generally safe. But there are a few things to keep in mind if you take them every day.
"Multivitamins, especially ones that contain iron, can upset your stomach," says Dr. Okunnu. "To reduce this, I typically recommend taking them with food."
It's why the best time to take multivitamins is usually at mealtime.
"Multivitamins that contain a lot of biotin — ones for hair, skin and nails, in particular — can lead to acne," adds Dr. Okunnu.
More concerning than these side effects, however, are the unknown issues that can result if you take a multivitamin that hasn't been third-party verified.
"With untested products, you can't truly know what you're taking," warns Dr. Okunnu. "This could lead to really significant problems and side effects if the product contains unlisted ingredients or additives that are harmful."
The last side effect of multivitamins Dr. Okunnu mentioned: the expense.
"Some vitamins these days are incredibly pricey," adds Dr. Okunnu. "Multivitamins may come with a lot of promises, but we don't know there's actually any benefit. Cost should be considered a big side effect in my opinion."
By: Katie McCallum