Are Multivitamins Right for Your Body?

People tend to make two types of mistakes when it comes to nutrition.

One of those errors is overthinking the small stuff. You agonize over questions like “how many meals should I eat?” (Answer: it doesn’t really matter so long as you’re hitting your overall daily needs.)

But then people also under-think questions. They tend to assign broad, sweeping value judgments to foods and supplements. They want to know whether whatever it is they’re taking is “good” or “bad.”

No matter what marketing will sell you, taking megadoses of vitamins does not bulletproof your immunity.

The problem is that, without knowing who you are and what you are trying to do, the question is meaningless. The only honest answer is, “It depends.” And as you already know, that response always feels like the worst answer in the world. It doesn’t help you get any closer to the answer you want.

That’s especially true for multivitamins. The overall data on them is conflicted. Read one article, and you find out they’re not going to make you live longer or prevent cancer. Or maybe you’ve heard that they cause cancer, but that suggestion is also false.

The mess led the National Institutes of Health to say that “it is not possible to recommend for or against” using them.

But there’s no need to throw your hands up in frustration. If you dig into the research, you’ll find that science has a clear picture of multivitamin’s usefulness for common fitness goals like losing fat or building muscle.  

In order to crack the multivitamin code, you just need to ask yourself two questions:

  1. Why do I want to take a multivitamin?
  2. What do I hope to achieve with it?

Should I take a multivitamin?” is a question that only you can answer, but it doesn’t have to be a difficult decision. The guide below will help you gauge a multivitamin’s usefulness for your wants and needs, and help you know the options (if you choose to use a multivitamin) that are safe and effective.

Do You Need a Multivitamin? Start here. 

Here’s an ironic fact: Most people use multivitamins as a nutritional insurance policy. Those who take them often follow healthier, more mineral-rich diets. When you think about it, the approach makes sense — healthier people are more likely to engage in health-ish behaviors. Unfortunately, the reverse is also true: People who eat less nutrient-rich diets are less likely to take multivitamins.

At least those that are avoiding multivitamins aren’t falling for the belief that taking a multivitamin can help offset the flaws of a terrible, junk food diet. Because they won’t. But that doesn’t mean that those with less-than-stellar diets don’t need a multivitamin.

If you want to consider taking multivitamins, you should do a quick self-assessment. That’s because certain people run a higher risk of nutrient deficiencies even with a healthy diet.

For example, women tend to have a greater risk of iron deficiency, especially when pregnant. Vegans and vegetarians are more likely to be deficient in Vitamin B12. Research indicates that most just about all of us are lacking in magnesium, zinc, and–especially–vitamin D.

When it comes to figuring out exactly what you need, your best option is to start by having a basic blood panel. Otherwise, you’re just guessing. Once you are armed with your results (and know where you are deficient), you can move on to finding answers and knowing if multivitamins are the right decision for your goals and needs.

Will a Multivitamin Help You With Fat Loss?

Let’s start with the most common goal in the health and fitness industry: fat loss. Unfortunately, multivitamins do not improve fat loss. If they did, everyone would take them—and then go skipping off for seconds at the soft-serve ice-cream machine, knowing that their six-pack abs were protected by this miracle pill.

Achieving fat loss largely comes down to being in a caloric deficit. You have to burn more calories than you consume. In the most basic sense, that means you either eat fewer calories or increase exercise and activity.

If you go the low-calorie route during a fat loss plan, you might run a greater risk of nutrient deficiencies due to you eating less or enjoying a smaller variety of foods. Now, ideally, when you’re on any plan, you’ll be eating plenty of fruits and vegetables. But reality doesn’t always follow ideal situations, so if the above scenario describes you, it might be a good idea to take a multivitamin.

That said, a word of wisdom: feeling hungry all of the time and eating only chicken and broccoli is both boring and unnecessary. Which is why we recommend you listen to the under-heard, more balanced voices in nutrition—people like Dr. Yoni Freedhoff, Alan Aragon, John Berardi and Mike Roussell. They won’t focus on restriction. They’ll tell you to eat more of the good proteins (meat/chicken/eggs/fish/plant sources), fats (oils, nuts, dairy sources, avocados, seeds), and carbohydrates (fruits, vegetables, rice, potatoes, grains) that you enjoy. You’ll probably be amazed at how much more full you feel—and how much longer that satisfaction lasts—even as you consume fewer total calories.

You know what else happens when you go with this approach? You’re more likely to meet your micronutrient needs. Making a multivitamin less necessary, or not needed at all.  

The verdict: Multivitamins have no benefits for fat loss, but they could help if you’re eating less and not enough vegetables, fats, and proteins.

Multivitamins and Muscle Mass

There is no evidence to support the idea that a multivitamin helps you to gain muscle mass. When you gain muscle, it’s primarily the result of a proper strength training plan combined with a diet that supplies adequate protein and calories, and enough sleep so your body can rebuild and recover.

One supplement that has consistently demonstrated that ability to assist with muscle growth and repair is protein powder. (Creatine has a host of muscle-building benefits too, but that’s a different discussion.) But even then, there’s nothing magical about the powder; it’s the role of protein that makes the biggest difference, whether it’s a supplement, meat, chicken, fish, eggs, or plant-based sources.

The verdict: If your goal is to add mass, your first priority should be to eat enough high-quality food to help you build it. Any muscle-building benefits claimed by a multivitamin are as of yet unproven.

Multivitamins, Energy, and Cognitive Function

Interestingly enough, Northumbria University in the UK conducted two studies—one of 216 females aged 25-50 years old, the other of 198 males aged 30-55 years old—and found that in both groups a multivitamin improved cognitive function, lowered fatigue, and improved subjects’ ability to multitask. The participants who took a multivitamin did better compared to the placebo group.

These two studies, on their own, are not reason enough to conclude that a multivitamin is your fix for mental fog or will stop you from nodding off at your desk at 3 p.m. It’s worth noting that the studies didn’t discuss a host of variables that could have a significant impact on the results, such as sleep, nutrition, or exercise habits of their participants. However, both studies were randomized, placebo-controlled, and double-blind, which is a fancy way of saying that they deserve attention and more research.

The verdict: If you’re looking for a low-risk, potentially effective way to beat fatigue and increase your energy, multivitamins are a good option to try.   

Will Multivitamins Help Prevent Sickness?

The performance of your immune system depends on a variety of complex factors. One of those is your micronutrient levels, which help create a defense system for your body. Specifically, vitamins A, C and E work along with zinc to help the skin barrier function, while vitamins A, B6, B12, C, D and E work along with a host of other trace elements to support the immune cells.

Nutrient deficiencies suppress your immunity. So for that reason, a multivitamin could be helpful. But then again, so could a smoothie that loaded with the above vitamins (here’s an easy-to-make one that we like that supports immune function).

It’s important to note that while nutrient deficiencies can hamper your immune function, the reverse is not true. Taking megadoses of vitamins does not improve your immunity. So you can put down the Airborne and slowly back away.

While most multivitamins contain the Recommended Daily Allowance (RDA) for vitamins and minerals, RDA is what’s required strictly to achieve the bare minimum level of health. In essence, RDA gives you what you need to survive, not necessarily to thrive and live optimally. It’s tough to say whether your specific multivitamin contains the right doses needed to bring your levels to an optimal range.

Even if its label says it hits all the RDAs, some multivitamins aren’t so beneficial as advertised because they use less-than-optimal components. A common example of this would be vitamin D2, which is less biologically active in the body than vitamin D3, and therefore less effective at boosting vitamin D levels. Similarly, studies show that magnesium citrate has superior bioavailability when compared with other forms of magnesium, but those other forms often end up in people’s daily multis.

The verdict: Similar to fat loss, be honest about your diet. If you’re not eating enough of the foods that are high in nutrient content, then it might be worth your while to boost your defenses by taking a multivitamin. Or, the easiest way to measure your deficiencies (as we mentioned in the beginning), is to take a blood test. Then, you can decide if you want to supplement your needs with whole foods or a multivitamin.

Men’s Multivitamin vs. Women’s: Is there a difference?

A common theme you’ll see from popular brands is age- or gender-specific multivitamins. There’s something to this idea. Men and women do have different nutritional needs, and those needs do change as you age.

For example, women who are menstruating have a higher need for iron than men due to the blood lost during menstruation. After menopause, women no longer need that higher iron intake. At that point, their iron needs equal those of men. But menopause brings about another change, this one to a woman’s need for calcium. Estrogen plays a role in calcium reabsorption and bone turnover, so with the decreased estrogen production that stems from menopause, a woman’s need for calcium increases.

The verdict: The idea that your multivitamin formulation should change over time has some merit. You’ll just want to subject any claims on the label to the same type of scrutiny you’d give any other supplement. The same facts still apply: The vitamin won’t cure cancer or add years to your life. It may provide more of the nutrition you need. 

Buyer’s Guide: Not All Multivitamins are Created Equal

Because multivitamins are categorized as supplements and FDA regulation of supplements is extremely hands-off, the quality can vary and it’s easy to purchase a product that might be less effective.

You can’t take the claims on a multivitamin’s label at face value because they aren’t managed by a governing body that holds them to a standard. There are, however, certain seals of approval from non-government organizations that can tell you if the supplement has passed their tests for quality, potency, and contaminants.

These seals of approval show that the supplement was manufactured properly and actually contains the ingredients listed on the label. (Which is important when you consider that false labeling is rampant in the supplement space.) They also test for the presence of harmful contaminants. Here are two that offer you a reasonable assurance that what’s inside the bottle matches what’s on its label:


U.S. Pharmacopeia – USP tests a supplement for four P’s: Positive Identity, Potency, Purity, and Performance. Positive Identity means the vitamins and minerals on the label are actually present in the supplement. Potency means those micronutrients are present in the proper amounts listed on the label. Many supplements on the market will have too much, too little, or none of some of the listed ingredients. Purity means the supplement does not contain unwanted ingredients, which could include heavy metals, pesticides, and even banned substances or pharmaceuticals. Lastly, Performance means the supplement will actually break down and be absorbed by your body. After all, if a supplement doesn’t dissolve in your digestive system, it won’t be of a lot of benefit to you.


NSF – NSF is an international health and safety organization that monitors many different types of products including kitchen appliances, water filtration systems, and even plumbing fixtures. When it comes to supplements, the NSF “Certified for Sport” label is especially useful for athletes. Any product bearing that label has been tested for banned substances and verified as safe.

Ideally, the multivitamin you buy would have both of these seals on its label. If it does, and the dosages listed meet at least the RDAs, it shows that multivitamin is more likely to be higher in quality than average. But you also should check the vitamin manufacturer’s website. There you should find more information on the production and testing process the company uses to ensure quality. (And if you don’t, there’s a warning sign for you.)  

Another way to check a product’s quality is to visit Labdoor. Labdoor is unique in that they buy supplements directly from retail stores then test them in an FDA-registered lab. Those supplements are then ranked by category based on how well they perform. While Labdoor hasn’t tested every product on the market (and some other ratings — like taste — are more subjective), you can find a breakdown of every multivitamin they’ve tested to date.  

Are More Expensive Multivitamins Better?

While the saying, “you get what you pay for” is oftentimes true, that’s not always true with multivitamins. In fact, some of the less expensive options are quite good.

Full disclosure: Born Fitness does not have any financial agreements in place with any of these brands. We’re including them solely based on what we know about them through their reputation, reviews, and other available information.

Thorne Research is a well-respected company in supplement space. They’re known for having extremely high standards for purity and precision. Thorne offers a wide array of NSF Certified for Sport supplements, and has partnered with the Mayo Clinic to run randomized, double-blind, placebo-controlled clinical studies investigating the effects of a variety of nutritional supplements. When it comes to multivitamins, all of Thorne’s offerings contain adequate amounts of the necessary micronutrients, including both vitamin D and K. They also offer several options tailored to those who have specific needs. For example, some of their formulations have copper, iron, or iodine removed for individuals who are sensitive to those nutrients. Thorne multivitamins range from $26.99 for 60 capsules to $44.85 for 180 capsules.

Garden Of Life also provides high-quality multivitamins, according to their test performance on Labdoor. Three of the top five ranked supplements on Labdoor are from Garden of Life. The brand’s multivitamins are USP certified. Garden of Life’s products cover a wide range of needs including specific offerings for men, women, and prenatal. Garden of Life multivitamins range from $34.54 for 120 capsules to $60.52 for 240 capsules.

Nature’s Way is a brand you’ve likely seen in your grocery store. Their Alive Max Daily ranks among the top 5 multivitamins on Labdoor. While you don’t see it on the bottle, they are an NSF certified company. The Alive Max Daily multivitamins cost $22.49 for 180 tablets. One thing to note is that The Alive Max Daily multivitamin contains large doses—ones that far exceed the RDA—of every nutrient it contains. You can take less than the recommended three-tablet dose if that is a concern.

Costco’s Kirkland Signature. If you’re on a tight budget, you’ll be thrilled to hear that Costco’s multivitamin performs really well in tests. The Kirkland Daily Multi is USP certified and ranks in the top 50 multivitamins on Labdoor. There’s nothing fancy about Costco’s multi—especially not the label—but it provides all the essential nutrients in an easily digestible form, and is extremely cost effective at $14.49 for 500 tablets.

To Take Multivitamins or Not to Take Multivitamins…

If you do decide to take a multivitamin, first be honest with yourself about your expectations. Research does not support the notion that any large-scale physical changes will result from a multivitamin alone.

From there, assess your needs. Bloodwork is the most thorough option. Age- or gender-specific vitamin formulations may be helpful.

For any multivitamin you consider, do your homework. Check the label. Look for seals from USP and NSF. Visit the manufacturer’s website, and see how the product scored on Labdoor.

Of course, you should also consult with your physician.

Whether or not you take a multivitamin, you still need to eat high-quality foods, exercise appropriately, and manage your sleep and stress. These are truly the low-hanging fruit when it comes to disease prevention and living a vibrant, healthy life.

Follow those rules, and you may find that you don’t need a multivitamin at all.


Fix Your Diet: Understanding Proteins, Carbs and Fats

How Many Eggs are Safe to Eat?

7 Supplements Worth Trusting


  1. Thank you for sharing such an informative article, it cleared all my doubt regarding supplements , will tell others too .

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.