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Reading the Fine Print: How to Find Trustworthy Vitamins on the Internet’s Largest Retailers

Most black markets hide in the shadow of commercial trade — down a back alley, around a VPN. Others operate in broad daylight under the authority of blindfolded regulators. The vitamin and supplements industry is simultaneously valued at $130 billion globally and classified as food, not drugs, by the U.S. Federal Drug Administration, which means it’s not nearly as tightly regulated as it should be. The result? It’s very difficult to find trustworthy vitamins online, and even the most health-conscious may end up swallowing lead, talc, or even shellac coating. 

Specifically, the FDA does not evaluate vitamins or supplements for safety, efficacy, quality, or consistency in regards to ingredients. That quality assurance process is left entirely up to individual manufacturers who often produce entire product lines for multiple brands, so any errors can have sweeping effects across many labels with vastly different price points. 

“The FDA is not checking on any of these products,” said Dr. Pieter Cohen, MD, an Associate Professor of Medicine at Harvard Medical School and an internist at Cambridge Health Alliance. “No one is checking to make sure they even contain what’s listed on the label.” 

Most people aren’t naive to this reality when it comes to supplements. They are, more than anything, victims of their own perceived biological imperatives. The human body needs. A vitamin is, purportedly, a naturally-occurring micronutrient in food taken in pill form. A supplement can be naturally-occurring or synthetic. Both can help boost a lackluster diet or physical deficiency. The the right buying advice can help in avoiding the pitfalls of spotty manufacturing practices. 

The Best Places to Buy Vitamins: At a Glance

Spring Valley Vitamin D3 Softgels

Buy Now $8.88 Jump to Details

Spring Valley Vitamin B12 Quick-Dissolve Tablets

Buy Now $7.96 Jump to Details

up&up Zinc Dietary Supplement Caplets

Buy Now $6.39 Jump to Details

up&up Iron Dietary Supplement Tablets

Buy Now $8.89 Jump to Details

Thorne Vitamin C with Flavonoids

Buy Now $18.00 Jump to Details

What the Experts Say

According to Cohen, the best shot at something trustworthy is single-ingredient supplements — like C, A, B — and it’s even better if they’re purchased at a huge box store like Walmart or Target. Why? Established brands have more to lose than earthy co-op labels if they fuck up.

“Most supplements are throwing in a lot of different ingredients,” said Cohen. “But the fact of the matter is that, more often than not, those ingredients haven’t been tested together and the brands are just coming up with a marketing plan to combine certain things.” 

Tod Cooperman, an M.D. and founder of ConsumerLab, an independent vitamin and supplement quality assurance organization, echoed this advice. “It’s just marketers saying, ‘This is hot, that’s hot, let’s throw it all into one formula.’ Everything that’s ever been related to sleep gets thrown into one formula.” 

Brands that appeal to a sort of farmer’s market elitism should also be approached with caution. The manufacturing resources and reputational stakes that come with a Walmart are a direct benefit to consumers, and can create a better product overall. 

“You may think, ‘Why would I buy my multivitamin at Walmart?’ But the truth is that the vendors have a lot to lose if they screw up,” said Cooperman. When discussing larger retailers in general he noted that they “really drive their suppliers hard to make a good-quality product at a very low cost, which is why you can get some of the best single or multivitamins or minerals there.” 

How to Shop for Trustworthy Vitamins Online

One way to decipher the more trustworthy brands from the junk is third-party testing. 

“Don’t just rely on one brand and certainly don’t just rely on a vendor or a merchant,” Cooperman said. “But you need to drill down to the product and make sure it’s been third-party tested. That’s really important.” (But be advised: some brands will falsely slap “third-party tested” on their labels without any vetting having taken place, so it’s important to pay attention to the seal and where it’s from.)

NSF International and US Pharmacopeia (USP) are among five trustworthy agencies, according to Cohen. If a brand works with one of these five, that can signal they’re more trustworthy than others. 

The five third-party seals Dr. Pieter Cohen recommends looking for on vitamin/supplement labels.

However, even if a brand has obtained one of these seals of approval, the manufacturing inconsistencies can make one bottle actually vitamin C and another an expensive placebo (and that’s the best-case scenario). 

Another way to boost a brand and product’s credibility before making a purchase is double-checking its ratings and reviews on a site like ConsumerLab.

The Best Places to Buy Vitamins Online


Cooperman pointed out Spring Valley specifically, Walmart’s in-house vitamin and supplement brand, as a more trustworthy option than niche labels from local co-ops or smaller grocery stores. Most of Spring Valley’s supplements are single-letter or single-ingredient, which makes it more likely that the contents of the bottle match the label. It also bodes well for the brand that it’s not pushing a ton of proprietary blend formulas. 

Here are a few of Spring Valley’s vitamins that SPY editors recommend investing in.

Courtesy of Walmart


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Spring Valley is Walmart’s generic supplement brand with a wide selection of single-ingredient products including these vitamin D3 softgels. They include a potent and active form of vitamin D, which can support proper calcium absorption for stronger bones and teeth.  

Courtesy of Walmart


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These B12 quick-dissolve tablets are formulated to support a healthy metabolism and energy levels with a cherry flavor to boot. They dissolve quickly in the mouth so they’re fast to take and each bottle contains a four-month supply.


Target’s another large retailer whose in-house brand is more likely to yield higher-quality supplements, according to our experts. Their up&up label has a bunch of tablet and gummy adult vitamins, as well as some blends aimed at things like “Hair, Skin and Nails,” which are less likely to be effective. Their website also dedicates a whole section to “Label Info” — essentially giving the customer a clear online view of the bottle’s label — which makes it easier to see the purported ingredients. Similarly to Walmart, single-ingredient or single-letter vitamins are the safest bet. 

Courtesy of Target


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These 50 mg zinc tablets are formulated to support immune health and serve as an antioxidant boost for those who don’t absorb enough zinc in their regular diets. 

Courtesy of Target


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Similarly to zinc, these 65 mg iron tablets are designed to supplement a diet that doesn’t contain enough iron, a nutrient essential for red blood cell formation. This supplement only contains iron and may help with fatigue. 


Amazon, as the internet’s largest retailer, can be a source of trustworthy vitamins but more tactfulness is required from the shopper. Any old brand in the search results shouldn’t be trusted, but a larger library — and not having to buy generic products — can be a pro for certain shoppers. 

Since Amazon doesn’t have their own in-house supplement brand to the extent of the other retailers, it’s more important to inspect the label for third-party testing from reputable sources like NSF, as well as shop for single-ingredient supplements wherever possible. 

Here are a few of the better options SPY editors recommend.

Courtesy of Amazon

$17.25 $24.69

Buy Now On Amazon

These gummies from Nature Made have a moderate dosage of melatonin and a pleasant strawberry flavor. They have a few more calories than other supplement options but it’s largely a negligible amount. Also, they don’t contain any artificial flavors, synthetic dyes, or high fructose corn syrup. 

Courtesy of Amazon

This pick from Nature’s Bounty is another one SPY editors recommend after research into the brand’s trustworthiness and transparency. The dosage is formulated to support blood cell reproduction and the budget-friendly price is a great value for a 90-day supply.


Thorne is a specialized health retailer that sells vitamins, supplements, and health tests. It’s known as a “professional brand” in the industry, meaning it produces supplements that are NSF-certified and that professional athletes can use under certain drug and performance enhancement restrictions. This means they can be more trustworthy, but no brand is entirely safe, according to Cooperman. 

“There are many people who say professional brands are supposed to be better,” he said. “They’re definitely more expensive — you can count on that! The quality tends to be better than average brands, but it’s not foolproof that you’re always going to get a good product with the professional brand.”

With that in mind, SPY editors recommend the following two supplements from Thorne.

Courtesy of Thorne


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This vitamin C contains naturally occurring citrus flavonoids, which can optimize the beneficial effects of taking vitamin C because it replicates the way the compound is found in nature.

Courtesy of Thorne


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This vitamin K from Thorne contains three essential forms of vitamin K — K1 and two forms of K2, including MK-4 and MK-7. This can help support bone density and healthy blood vessels, as well. 

Since the supplement industry feeds off of fabricating medical necessity and creating an artificial need in its consumers, vetting which supplements may work best for you — and doing your due diligence about each one — is an important first step.

And then moderation. “Where we see people actually get hurt by supplements is when they get very excited about some particular ingredient and overdo it.” said Cooperman. “[Problems arise when] they think they should be taking more of it than [is advised], because they’re so fixated on that particular supplement. Use moderation. More is not better. Do your research.”