A few companies questioned CR’s findings or told CR that their internal testing, whether for the same lots of products as in CR’s tests or more broadly, didn’t match CR’s results.
Amazon (whose in-house brand is Mama Bear) stated that its finished products undergo rigorous quality control testing to ensure they meet the labeled potency specifications throughout their shelf life and challenged CR’s methodology and results, saying the findings “do not accurately reflect this product’s composition.”
A spokesperson for Nestlé Health Science, which makes Garden of Life and Pure Encapsulations, told CR: “Our technical assessment noted differences between the analytical methods reported by Consumer Reports and those used by the qualified third-party laboratories supporting our testing programs. These methodological considerations should be taken into account when evaluating and comparing the reported results.” The spokesperson said that, based on the company’s experience testing this product category, historical testing data, and its established testing program, they “remain confident in the quality, safety, and nutritional profile” of the products in CR’s tests.
Piping Rock (which makes Li’l Critters and Nature’s Truth) told CR that its internal testing of Li’l Critters confirmed that the nutrient levels of the products in the same lots CR evaluated “met specification at the expected levels at the time of release of the product.”
Renzo’s, which is produced by Solara Labs, shared that its internal testing uses a different method for testing its melting tablets: “Our Renzo’s Multivitamin with Iron is formulated in a specialized orally dissolving dietary supplement matrix tablet which may present unique analytical challenges related to extraction efficiency and analyte recovery,” a spokesperson said, noting also that analytical results for vitamins and minerals may vary between laboratories.
SmartyPants also shared that it uses a different methodology for testing certain nutrients in its gummy formulas, notably vitamin A, which, in CR’s tests, had one lot that landed below the USP tolerance threshold of 90 percent. “Our testing uses a USP-based method designed to account for the specific form of vitamin A used in our formulation,” the spokesperson said.
CR’s scientists remain confident that the testing methods used are appropriate for the different supplement formulations in our tests.
Our analysis found that two products, including those from Equate (Walmart) and NaturesPlus, had some nutrient levels that landed above the tolerable upper intake limit for some age groups, even though the vitamins were intended for children of those ages.
A spokesperson for Walmart told CR: “We are committed to providing safe, high-quality products, and work continuously with our suppliers to review and help ensure standards are met.”
We did not receive a response from Natural Organics, the maker of NaturesPlus supplements.
Though we received a customer service response from Nature Made, we didn’t hear back from parent company Pharmavite, which also makes MegaFood supplements, despite repeated requests for comment.
Ventura, the spokesperson for CRN, acknowledged that testing nutrient levels in finished dietary supplement products is complex.
“The accuracy and reliability of analytical results can be influenced by numerous factors, including the product’s formulation, ingredient interactions, nutrient forms, and the presence of other components that may interfere with testing … While manufacturers are responsible for ensuring their products meet applicable quality standards, it is important that conclusions about nutrient content are based on scientifically appropriate testing methods that account for these complexities,” Ventura said.
“CR understands that product formulations can be complex and provide potential interferences. That’s why CR mitigates these issues with quality control tests, such as matrix spikes, and by using ISO-accredited laboratories and validated methods. We also test multiple lots to see if we get consistent results,” says Boring, who led CR’s analysis.