Clearly, better laws for supplements are needed. Proposals to strengthen DSHEA come up periodically, but they never get far in Congress. It is unreasonable that medications (prescription and over-the-counter) are subject to the rules of science and strict laws, while dietary supplements conform to few rules except those of the marketplace. This leaves not only the public but also medical practitioners in the dark about how and whether dietary supplements work. More well-designed scientific studies of supplements are urgently needed. The public needs and deserves enforceable standards to ensure quality and purity as well as established criteria for both safety and efficacy. Herbal remedies, in particular, need to be standardized so that purity and potency do not vary from batch to batch. Finally, the FDA needs adequate resources to enforce the laws and standards.
Taking high-dose supplements of the B vitamin biotin can throw off the results of some common diagnostic blood tests. Many people take biotin in hopes of stimulating growth of hair and nails or for other unproven health reasons.
In a small study in the Journal of the American Medical Association in 2017, healthy adults took 10 milligrams of biotin a day (a commonly used megadose, about 300 times the daily RDA) for a week and then underwent a variety of common immunoassay blood tests, including some for thyroid hormones. Some results came in falsely high, others falsely low, which could result in misdiagnosis and incorrect treatment.
The problem is that biotin is a critical component of some immunoassay tests, and thus high blood levels of the vitamin can lead to inaccurate results.
If you take biotin and are having blood tests, ask your doctor to check if any of them are affected by biotin. If so, you may be advised to stop taking the supplement for at least a week before being tested—or stop it altogether, since it’s unlikely to be doing you any good.
In 2017, the FDA warned about biotin supplements—see tinyurl.com/biotinFDA2.
A Checklist for Supplement Users:
• Beware of anecdotal evidence and celebrity endorsements in ads or on the Internet. You can never be sure whether testimonials were paid for or made up by a copywriter. And for every person who was helped, ten may have seen no benefit or even gotten worse, and such negative results never turn up on websites or in ads. Even if they are real comments from actual customers, testimonials are unscientific “evidence” of benefits. And according to the FDA and FTC, companies are prohibited from posting
or reprinting testimonials that make medical claims the companies would not be allowed to make directly. Medical claims in marketing are strictly regulated and must be supported by adequate clinical data.
• Be wary of anti-aging claims. So far there is no supplement or any known substance that will help keep you young, unfortunately.
• Be skeptical of ads or websites claiming that doctors don’t want you to know about the cure-all supplements they are promoting because these products will hurt the doctors’ business.
• Talk to your doctor, pharmacist, or other health care provider. Tell them about any supplements you are taking. Many supplements, notably herbal products, can have adverse effects when taken with prescription drugs. And don’t rely on supplements to self-treat a serious health problem—see your doctor for a proper diagnosis and recommendations on treatment.
Be very skeptical of testimonials on websites and in ads for dietary supplements and other health-related products. Even if they are real comments from actual customers (often they are paid actors), such testimonials are unscientific “evidence” of benefits. And according to the Food and Drug Administration (FDA) and Federal Trade Commission (FTC), companies are prohibited from posting or reprinting testimonials that make medical claims the companies would not be allowed to make directly. Medical claims in marketing are strictly regulated and must be supported by adequate clinical data.
The agencies have been cracking down on testimonials that cross the line, but new ones keep popping up. It’s not enough for marketers to make vague disclaimers like “results may vary” in small print under testimonials.
