It’s not uncommon for some segments of the population to take a handful of vitamins or supplements each day. About 15% of adults report using four or more supplements. Among older adults, the number who report using multiple supplements is even higher, with about 25% of adults over 60 taking four or more types. About 35% of children and adolescents use supplements, and about 10% of children ages 2 to 5 take two or more types of supplements.
Experts say vitamin and mineral supplements are generally safe when taken in small to moderate amounts, such as those found in a basic multivitamin. Dietary supplements can be beneficial for pregnant women and people with nutritional deficiencies or other health problems. A clinical trial conducted earlier this year found that people over 60 who took a daily multivitamin slowed memory decline. Other studies have found that probiotic supplements can help with gastrointestinal disorders such as irritable bowel syndrome.
However, taking supplements carries risks, and studies aren’t always clear whether the benefits outweigh the risks for most healthy adults.
In fact, several randomized trials have shown that when participants were asked to take supplements containing large amounts of beta-carotene, selenium, and vitamins A, C, and E, Increased Mortality. Rigorous clinical trials have not supported the hype around vitamin D, finding that people instructed to take the popular supplement did not experience reduced rates of cardiovascular disease, cancer, or fractures, despite widespread marketing claims to the contrary.
Supplements don’t follow the same rules as drugs
Many people believe that the Food and Drug Administration tests supplements for safety, but this is not the case.
“Dietary supplements are on the market before they have been fully reviewed by the FDA,” said Amy B. Cadwalader, director of regulatory and public policy development at the United States Pharmacopeia, a nonprofit organization that tests the quality of drugs, foods and dietary supplements.
Federal law allows companies to operate honestly, and the FDA’s role in regulating supplements is primarily to ensure that products are safe and accurately labeled after they hit the market.
Are you getting what you pay for?
In the United States, companies sell an estimated 90,000 dietary supplements in an industry worth roughly $50 billion. As a result, some experts say consumers who buy supplements can’t always be sure they’re getting what they pay for. Studies of melatonin, fish oil, probiotics, ginkgo biloba and other supplements have found that the dosage and ingredients listed on the label often differ from what’s in the bottle.
- In one study published in the journal Pediatric Research, researchers tested 16 probiotic supplements and found that only one contained the specific strain of bacteria listed on the label.
- In another study, researchers tested 30 supplements claiming to boost the immune system and found that 17 of them were “misbranded” – they either did not contain key ingredients listed on the label, such as vitamin B12, garlic extract, ginger root, and folic acid, or contained a variety of unlisted ingredients.
- One FDA study estimated that less than 1% of all adverse events related to supplement use are reported to the FDA. Another federal study estimated that supplement-related injuries result in approximately 23,000 emergency department visits each year.
Howard Lux, a New York orthopedic surgeon and sports medicine specialist, said he often encounters patients who are worried about medication side effects but are okay with taking 10 to 20 supplements they heard about from social media health influencers. He said many people who have lost trust in public health authorities during the pandemic have turned to social media influencers for health advice.
“They believe that supplements are holistic and natural and therefore not potentially harmful to them,” he said.
In a case study published in March, doctors in New Jersey reported the case of a 76-year-old woman who visited the emergency room with symptoms including palpitations, dizziness, and fainting. It turned out that the woman had been taking black cohosh, an herbal supplement commonly used to treat hot flashes. A few days after she stopped taking the supplement, the woman’s heart rate returned to normal and her other symptoms disappeared.
In another recent case, a 47-year-old Houston woman developed jaundice and liver damage after taking a supplement containing a mixture of probiotics and herbal extracts. Case reports suggest that dietary supplements are responsible for about 20 percent of drug-induced liver damage nationwide.
How to buy supplements wisely
Here are some tips to consider when buying supplements:
Look for third-party certifications: The United States Pharmacopeia (USP) tests dietary supplements to make sure they meet high standards for purity, potency, and other factors. USP has a voluntary program that allows companies to regularly test and inspect supplements and facilities. Companies that meet the organization’s high standards can use the black and yellow “USP Verified” logo on their products. You can find these logos using the product search tool on the USP website. NSF is another independent organization that tests and reviews dietary supplements. Look for the blue and white “NSF” logo on supplements or search for products on the organization’s website.
Do your homework. Consumerlab.com is an independent laboratory that tests dietary supplements to ensure they contain the ingredients and dosages listed on the label. The company publishes reports summarizing its findings on various supplements, which can be accessed on its website for a fee.
Consult your doctor or pharmacist“Many supplements and medications use the same metabolic pathways, and what many people don’t realize is that taking them together can have dangerous side effects,” says Michael Hsu, assistant professor of pharmacy, family medicine and palliative care at the Mayo Clinic in Florida.
For example, vitamins E and K, ginseng, ginkgo, resveratrol, turmeric, and CoQ10 may interact with blood thinners. Vitamin C may interact with statins, niacin, estrogen, warfarin, and chemotherapy drugs. St. John’s wort may decrease the effectiveness of antidepressants and birth control pills.
“You see that with a lot of supplements,” Hsu says, “even something like resveratrol extracted from grape skins, when taken in a concentrated form, can interact with a lot of medications.”
Have questions about healthy eating? Email EatingLab@washpost.com Maybe I’ll answer your question in a future column.
