f you’re consuming a tablet or capsule every day, you’d better know exactly what’s in it and how much. Unlike pharmaceuticals, supplements aren’t submitted for FDA testing and approval before they go to market. The FDA does require that manufacturers disclose all supplement ingredients and detail the amounts per serving — unless it’s classified as a “proprietary blend.” In that case, the manufacturer doesn’t have to disclose anything besides a list of ingredients and the total amount in the bottle (you won’t see suggested daily values here).
This kind of disclosure loophole originated to protect businesses with unique products from being copied from competitors, but it’s also a convenient way for manufacturers to skimp on amounts or use inferior ingredients. What’s worse, buyers could end up consuming a product with too much of one ingredient — even an herbal add-in — which can pose health hazards. (For example, seemingly harmless herbs such as licorice and ginseng have been tied to high blood pressure.)
To make sure these vitamins contained the ingredients they claimed, we cut products that didn’t have credible third-party verification. Without FDA oversight, the supplement industry is a bit like the Wild West of the wellness world. Journalist Catherine Price researched the supplement industry while writing her book, Vitamania: How Vitamins Revolutionized the Way We Think About Food, and she told us if there’s one thing consumers should know, it’s this: “Dietary supplements are not tested for safety or effectiveness before being sold. The motto of the industry should be caveat emptor: buyer beware.”
We cut all multivitamins that weren’t approved by or compliant with at least one of the following:
NSF and USP (both nonprofit organizations) test supplements at the request of manufacturers, then lend stamps of approval to verified products’ packaging. Labdoor and ConsumerLab, both for-profit companies, seek out products to test without consent from manufacturers. (Manufacturers can request tests from ConsumerLab as well).
We also looked for products that were in compliance with the International Organization for Standardization’s (ISO) system of in-house testing. This international non-governmental organization lays out a rigorous system of testing for quality management for any product; MegaFood, the manufacturer of our top picks, is in compliance with that system. It’s not an independent certification, but it usually demonstrates that a company cares about quality assurance and wants the public to know.
“Inactive ingredients” is a blanket term for everything included in the pill that isn’t adding nutritional value. Typically, a short list of inactive ingredients is a good sign of quality — our top picks from MegaFood have just three.
We looked for formulas that limited their use of artificial sweeteners, including sucralose, dextrose, maltodextrin, xylitol, glucose syrup, aspartame, and high fructose corn syrup. These ingredients don’t make your vitamin more nutritious; most of them just make it sweeter. We also wanted to avoid partially hydrogenated oils, artificial colorants, fillers, and binders (like titanium dioxide, carmine, benzoic acid, butylated hydroxytoluene, PEG 3350, talc, and magnesium silicate).
We turned to the FDA’s dietary guidelines to gauge vitamin consumption. Out of the 27 nutrients the body needs, the FDA states that American adults are most likely to be at risk of not consuming enough calcium, potassium, or magnesium — as well as vitamins A, C, and E.
Although we searched, very few multivitamins contain significant amounts of everything. “Multis don’t typically contain 100% of what you need, as the pill would just be too large,” Sharon Palmer, a registered dietitian nutritionist and author of Plant-Powered for Life, told us — and in fact, we even had trouble finding a good option that included all those key “at-risk” nutrients, particularly potassium and calcium.
It’s understandable: there’s no way one supplement could magically cover all the bases for all people. So to make our top picks, we analyzed our remaining list of 33 multivitamins, looking for the ones that featured the fewest inactive ingredients, the best third-party certifications, and the most well-rounded roster of nutrients.