8 Secrets Vitamin Manufacturers Don’t Want You to Know

Updated: Aug. 17, 2021

Roughly half of Americans take some sort of vitamin or supplement every day to improve their health and well being, but what we don't know about how these pills and potions are made may be hurting us.


Risky fillers

The same artery-clogging hydrogenated fats and oils (aka trans fats) that we are told to avoid for health reasons are also used as cheap vitamin fillers! That’s just one filler to watch out for, warns Elissa Goodman, a holistic nutritionist in Los Angeles, CA. Another is magnesium Silicate (aka talc), which is used in supplements as a filler and anti-caking agent. (Anti-caking agents prevent lumps and bumps.) “Magnesium silicate is similar to asbestos in composition and can cause stomach and lung problems when inhaled or ingested,” she says. Avoid these risky fillers by reading label. And “if you see any ingredients you’re unfamiliar with, look them up,” Goodman adds. Here are more vitamin myths you need to stop believing.


Dangerous dyes

Nutritionists generally recommend getting the nutrients you need from food instead of supplements, and exposure to dyes is one of the reasons. Just like crayons, vitamins tend to come in an array of rich colors, “but there’s really no legit benefit to having vitamins dyed a specific color, and these dyes have been linked to everything from allergies to behavior problems,” Goodman says. They are only added to offset color loss from exposure to light, air, temperature extremes, moisture, and other conditions, or to enhance the appearance of the vitamin. In just one example of the risks, titanium dioxide, a color additive that makes tablets and capsules bright white, may cause lung, kidney and intestine inflammation, according to Goodman. The American College of Healthcare Sciences in Portland, OR, urges supplement takers to steer clear of these dangerous dyes: FD&C Blue No. 1, FD&C Blue No. 2, FD&C Green No. 3, FD&C Red No. 3, FD&C Red No. 40, FD&C Yellow No. 5, and FD&C Yellow No. 6.

“Color in natural foods is good. Color in your supplements—not so much,” adds Boston-based nutritionist Dana Greene, RD.


Mercury, lead, and cadmium

Your “healthy” vitamins could be filled with contaminants. Omega-3 fatty acids are a popular choice among supplement takers looking to improve their heart health, but it’s buyer beware when it comes to these pills. Fish can have dangerous levels of mercury, lead, and other contaminants that may make their way into fish oil supplements. Another favorite healthy supplement—cocoa powders, chocolates, and other products made from cacao beans—may be contaminated with high amounts of cadmium, according to a study by ConsumerLab.com in White Plains, NY.

And don’t be fooled by the “organic” label stamped on the vitamin bottle either, says Tod Cooperman, MD, president of ConsumerLab.com. “We all put too much faith in this,” he says. “They may not have used any pesticides, but there may just as much lead and other heavy metals in organic supplements as those not labeled organic.” Goodman adds that you should “ensure your supplements are tested for contaminants like lead, mercury and polychlorinated biphenyls (PCBs).” The label should offer guidance.


Outdated labels

You can’t believe everything you read—especially when it’s written on vitamin labels, warns Dr. Cooperman. “Current labels are wrong because the daily value (DV) information on the panel was updated in July 2016, but manufacturers are given time to comply with the changes,” he says. Labels won’t be fully updated until July 2019. This may result in your getting too much or too little of a given nutrient. For example, if you are taking folic acid you may be getting as much as 70 percent more of this B vitamin than you need based on the older DV information. “There is an upper limit for folate from folic acid and we know that very high levels can cause kidney damage or mask vitamin B12 deficiency,” he says. By contrast, relying on the DV for vitamin D could put you at risk for a shortfall of this vitamin’s effects. The new DV for vitamin D is 800 milligrams (mg), but if an outdated label says the supplement has 100 percent of the DV, it provides markedly less than 800 mg, he says. “You can get yourself in a situation where you think you are doing their right thing and are really getting more or less than you want or need.” Better safe than sorry. Check out the updated DVs, and make sure you know the telltale signs of a vitamin deficiency.


Overinflated potency

You are not always getting what you think when you buy vitamins, Dr. Cooperman reveals. “Companies routinely put in up to 30 percent more than they claim on the label to make sure the vitamins remain potent through the date of expiration.” Avoid this by looking for the “U.S. Pharmacopeia Verified” mark, which means that the quality, purity, and potency of the raw ingredients or finished products are verified by U.S. Pharmacopeia (USP). This stamp assures you that the product does, in fact, contain the ingredients listed on the label and that it has been made according to the US Food and Drug Administration (FDA)’s Good Manufacturing Practices. USP maintains a list of verified products on its website. In particular, look out for these vitamins that are a waste of money and could be dangerous.


Upper limits may be MIA

You can overdo it on nutrients, and labels won’t give you that type of guidance, Dr. Cooperman says. Vitamin labels do not have to list Upper Tolerable Intake Level, and in some cases, this can put your health at risk. Adults who get more than 2,000 mg of vitamin C (the upper tolerable unit), for example, may set themselves up for diarrhea, stomach cramps, and nausea. Talk to your doctor about what you need and how best to get it. Don’t fall for these other vitamin mistakes you don’t realize you’re making.


They are not cure-alls

No vitamin, mineral, or supplement can say that it can treat, prevent, cure, or reverse any disease or condition, according to the FDA. If a claims sound too good to be true, it probably is. Buzz words to avoid on labels include “totally safe” or “no side effects,” the FDA states. “As an RD, I prefer that my clients get the vitamins and minerals that they need from whole foods—not supplements,” says Greene. “Supplements don’t replace all of the nutrients and synergestic benefits found in whole foods.” There is a place for supplements, she says: “When it comes to preventing risk for diseases, it’s the big picture diet and lifestyle that matter most. There is no magic pill.”


We play by our own rules

Dietary supplements and herbs are not wholly regulated by the FDA in the same manner as foods and drugs. Unlike drugs, dietary supplements do not need FDA approval before they are marketed. Under the Dietary Supplement Health and Education Act (DSHEA), vitamin manufacturers are essentially responsible for ensuring that a supplement is safe before it is marketed. The FDA can, however, take action against any supplement that is misbranded or misleading in its labelling. For these reasons, the FDA suggests contacting the manufacturer about the product they intend to purchase. Check out these 14 simple ways to make your vitamins more effective.