It’s widely touted as a nutritional superstar, vitally important for bone strength, blood pressure, and even mental health. So if you don’t get enough sun, there’s good reason to rely on vitamin D supplements to obtain enough. Alas, new research reveals that your bottle of pills might not be living up to what the packaging promises. A group of Portland-based researchers tested 55 different over-the-counter vitamin D tablets, produced by 12 different manufacturers. Their analysis, published in the Journal of the American Medical Association, concluded that the pills contained as little as 9% to as much as 140% of the doses advertised on the bottles. Those wild variations are likely because supplements aren’t regulated by the Food and Drug Administration (FDA), meaning there’s little oversight into what they contain. For those of us inadvertently taking too much vitamin D, there’s little cause for concern, says lead study author Erin LeBlanc, MD, an epidemiologist at The Center for Health Research. “For most people, getting a little extra vitamin D isn’t going to cause harm,” Dr. LeBlanc says. Unfortunately, some individuals might be taking tablets that don’t contain adequate levels of the vitamin. “The real risk in terms of health is for consumers who have low vitamin D,” she notes. “When your doctor tells you to take ‘this much’ vitamin D, they’re expecting you’re going to get that much.” While the FDA doesn’t oversee the potency of vitamin D, another agency does: The United States Pharmacopeial Convention (USP) is a non-profit that verifies the contents of supplements for companies who request (and pay for) the process. Products that meet USP standards (pills need to contain 90% to 110% of the listed dosage) can then be labeled with a USP-verified seal. Unfortunately, Dr. LeBlanc says, few companies opt to undergo the screening: Of the 12 manufacturers her research tested, only one had been approved by the organization. It might take a little extra effort, but you should be able to find USP-certified products (Nature Made and TruNature are two examples) at most pharmacies. Verified supplements will carry a gold, black, and green USP sticker on the label—and, of course, they’ll contain the quantity of vitamin D you’re expecting. More from Prevention: Is Your Medicine Cabinet Out-Of-Date? Questions? Comments? Contact Prevention’s News Team.
