The popular health story of the past week, picked up from ABC News to Yahoo and across the gamut of health blogs, focused on a new study that revealed wildly inaccurate labeling of Vitamin D products for sale on drugstore shelves. Published Monday as a (subscriber-only) research letter for JAMA Internal Medicine, the study by Kaiser Permanente Center for Health Research endocrinologist Erin LeBlanc reported troubling discrepancies between the labeled and actual potency of 55 products tested.
The statistic used most frequently in the wave of media coverage, and for good reason, is that the actual amount of Vitamin D in LeBlanc’s sample ranged from nine(!) to 146 percent of labeled dosages. And most stories offered practical information to help drugstore shoppers be more judicious in their choices of supplements. For example, consumers should check product labels for the logo of the US Pharmacopeial Convention (USP), which works to protect quality and purity standards in the absence of FDA regulation. The coverage also at least explored the possibility that the troubling range in potency means supplement users may be getting too little or too much Vitamin D without knowing it, and both can be harmful.
But just about all the media coverage missed an opportunity to make an equally important point—that without medical advice to do so, nobody should be taking Vitamin D or any other supplement.
Research shows that there are benefits to taking Vitamin D supplements for those who are deficient, such as better bone health, and the vitamin may play a role in lowering the risk of certain types of cancers. But there is also controversy in the medical literature, spurred in part by a 2010 Institute of Medicine report, about how common deficiency is, how wide-ranging the benefits of supplementation are, and what are appropriate dosages for various populations, such as adults with medical conditions. And the average person is likely to be unaware of multiple factors that are considered in a prescription for Vitamin D, such as age, gender, weight, potential drug interactions, allergies, skin pigmentation, physical activity level, climate, and season. Most readers also may not know what while Vitamin D toxicity can cause mild side effects such as nausea, vomiting, and constipation, it can also lead to kidney stones and heart rhythm problems.
That complicated picture wasn’t captured by most of this week’s coverage, from USA Today to Forbes.com to Health News Daily, which mostly focused on the benefits of supplementation and the risk of getting too little D in your pills—and in the process, may have encouraged readers to go out and take as much of the stuff as they can. Writing at Forbes, Melanie Haiken even noted that “the most variability was found in pills and capsules containing 1000 ius of vitamin D3, so it might make sense to purchase lower dosage pills (and then take more of them).”
To a point, that framing is understandable. The conclusions of the IOM report are contested. And LeBlanc, in interviews with media outlets, mostly focused on the concern that supplement users may not be getting as much of the vitamin as they think they are.
But it’s well-known that consumers are always on the lookout for quick fixes for their health problems and respond, without the necessary research, to TV sound bites and exciting headlines. So it behooves health journalists to add one measly sentence to their stories about the fact that supplements can be just as toxic and dangerous as prescription drugs—and that they should be treated with the same respect and caution.
Among this week’s reports, the ABC News write-up by Nick Wasson did better than most in getting a range of medical perspectives and exploring the full spectrum of risks. But the strongest account probably came from Denise Mann, writing for HealthDay, which is picked up by WebMD and consumer outlets. She wrote:
Dr. Susan Zweig, an endocrinologist and clinical assistant professor of medicine at NYU Langone Medical Center in New York City, expressed more concern.
“It is hard to get toxic levels vitamin D, but it is certainly possible,” Zweig said. “Vitamin D is stored in fat so it can build up, unlike other vitamins that we pass when we urinate.” People with liver or kidney conditions may be at higher risk for vitamin D toxicity, she said.
As cliché as it sounds when you hear it, there’s a reason pharmaceutical commercials end with “Ask your doctor if it’s right for you.”
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