The last time I went to the doctor, I was handed a stack of paperwork and prompted to update my medications. All my usual prescriptions were already on file, but I paused to consider whether I really needed to itemize every single supplement in my medicine cabinet. Did it matter that I took the occasional probiotic or cranberry extract, that I was semi-regularly taking vitamin D or that I’d recently popped a melatonin during a bout of sleeplessness?
The answer: It probably mattered. But I let laziness prevail as I handed in my forms with a blank space after “other medications.”
My long mental list of supplements felt absurd to me, but I’m not an anomaly. Seventy percent of adults between the ages of 18 and 34 use supplements, according to a 2016 survey by the Council for Responsible Nutrition. That’s up from 65 percent in 2015.
Millennials in particular are embracing alternative medicine, whether or not it’s entirely rooted in science. Amy Gorin, a dietitian nutritionist, says a growing number of her clients are curious about the benefits of supplements like probiotics and omega-3s for preventive reasons. Whether they discuss those supplements with their primary care doctors is another question.
“They might be embarrassed about having a long list of supplements,” Gorin says, “or they may feel worried that the physician may not agree with the patient’s need for a certain one.”
Nevertheless, Gorin says it’s important to be forthcoming about the supplements you’re taking, even if you think your daily multivitamin is no big deal or you’d rather not chit-chat with your PCP about your CBD gummies. “I would err on the side of caution and always disclose.”
Not convinced? Here are a few reasons to be open and honest the next time you’re updating your paperwork in the waiting room.
Supplements can cause adverse drug interactions
One of the most important reasons to be candid about your supplements is to help your doctor identify potentially dangerous drug interactions. Herbal supplements may seem innocuous, but many have drug interactions worth knowing about.
The herb fenugreek, for example, can adversely affect diabetes medications and anticoagulants. Calcium supplements may decrease absorption when taken with medication for osteoporosis. And in a 2014 study, the anticoagulant warfarin was shown to interact negatively with a slew of common herbal supplements, including cranberry, chamomile and grapefruit.
Supplements can also decrease the effectiveness of your medications. If you add a green tea extract to your regimen and then your doctor prescribes Ambien for insomnia, the caffeine in the green tea might counteract the sleep-inducing effects of the Ambien.
In some cases, drug interactions can even be life-threatening. “There actually are fatalities associated with people taking St. John’s wort especially and having organ transplants rejected, and the patient ultimately dies because of that,” says D. Craig Hopp, deputy director of the division of extramural research at the National Center for Complementary and Integrative Health.
You should also discuss your supplements with your anesthesiologist before undergoing any surgery or medical procedure, according to the American Society of Anesthesiologists. Garlic, ginkgo and ginseng, for instance, can increase the risk of bleeding with anesthesia, and sleep and anxiety aids like valerian and kava can increase or prolong the effects of anesthesia.
You could be getting too much of a good thing
If you start your day with a supplement cocktail, it’s easy to overdo it inadvertently; you could be consuming too much of a particular vitamin, mineral or herb. That excess can lead to minor (but still unpleasant) side effects, like nausea from too much zinc or vitamin C, or more serious consequences like vitamin D toxicity.
High quantities of supplements can also skew blood tests. The FDA recently warned that high doses of biotin, also known as vitamin B7— a vitamin commonly found in hair, skin and nail growth supplements, multivitamins and prenatal vitamins — can botch the results of certain diagnostic tests. The FDA has reported at least one known fatality after a patient’s high biotin levels led to a false low result during a test for troponin, a biomarker that helps diagnose heart attacks.
“Natural” doesn’t always mean “benign”
Many patients think of supplements as harmless add-ons that promote wellness rather than “real” medications, Hopp says. That mindset often leads people to underestimate the impact of the pills or tinctures they’re using.
“I think people assume these things are safe, if not benign, and that they’re not really medicine,” Hopp says. “They don’t appreciate the significance of why they should divulge this information to their doctors.”
All products, even ones labeled “natural” or those that come from plants, have the potential to cause irritation, Hopp says. Products in the daisy family, such as chamomile and butterbur, have a particularly high propensity to cause allergic reactions in people with certain plant sensitivities.
It’s not only oral medications that fall under the umbrella of “supplements.” You’ll sometimes find supplements in energy bars, teas or other drinks, and Hopp says to be careful with any products you apply topically, like essential oils or CBD lotions and creams. The National Association for Holistic Aromatherapy cautions that some essential oils should be diluted prior to application to avoid skin reactions.
Bringing up supplements in the exam room
With around 30,000 different supplements on the market, Hopp says it’s unlikely that your doctor will have an encyclopedic knowledge of every nut oil, flavonoid and botanical extract. But your doctor should be familiar with some of the most common products and be able to point you in the right direction for more information.
You can do research on your own with the help of the NCIH’s HerbList app, which has a searchable database of popular herbal supplements, including detailed information about drug interactions, side effects and each herb’s effectiveness. You can also look up potential interactions in the National Medicines Comprehensive Database or the Drugs Interactions Checker at Drugs.com.
The next time you go the doctor, Hopp suggests bringing your supplements along. (Alternatively, if you have an overflowing medicine cabinet like me, snap photos on your phone of each supplement label.) That way, your doctor can see exactly what you’re taking and in what quantities. It might feel like overkill to dump out a tote bag of supplements in the exam room, but the more information you can offer your provider, the better.
“You never know what information is going to be important,” Hopp says. “Disclosing all the information that you can when you go to your doctor might save your life one day.