6 Supplements Doctors Actually Take

These days, it seems like everyone is taking a supplement—to look better, think better, sleep better, relax better, poop better, or work out better. And you’re not imagining things: Half of adults and one-third of children in the United States take supplements regularly, according to the Office of Dietary Supplements.

Supplements may be ubiquitous, but many experts have serious reservations about their rise. First, most physicians recommend obtaining nutrients directly from food rather than a pill or capsule. Second, supplements aren’t reviewed for safety and effectiveness by the FDA before they hit shelves. Because of all the concerns surrounding supplements, Jeffrey Linder, MD, MPH, a general internist and professor of medicine at the Northwestern University Feinberg School of Medicine, takes a dim view of the category overall: In fact, “a vast majority of supplements are probably worthless,” he tells SELF.

Still, there are exceptions to every rule—and supplements are no different. Many experts, as it turns out, do take some type of supplement, but they are choosy about which ones they select. Read on to learn more about six they actually use.

Vitamin D

How it works: Vitamin D plays key roles in bone health and immune function. In fact, low vitamin D is associated with a wide swath of medical conditions, according to Dr. Linder—including cancer, autoimmune diseases, infectious diseases, and cardiovascular issues (and, famously, seasonal affective disorder, or SAD).

Why some docs like it: Vitamin D deficiency is widespread, especially among people who live at northern latitudes that don’t see as much sun during the winter, and people with darker skin. What’s more, few foods contain significant amounts of vitamin D, so it’s tough to source enough from your diet. Lawrence Green, MD, a dermatologist and clinical professor at the George Washington University School of Medicine and Health Sciences, tells SELF that these two factors make vitamin D a rare nutrient “we do need to take supplements for.” Nearly every single one of the eight doctors who spoke with SELF for this article said they take a vitamin D supplement, especially in the winter, though the frequency and dosage varied.

What to keep in mind: Most docs recommend vitamin D3 (also known as cholecalciferol) over vitamin D2 (also known as ergocalciferol), as studies have shown that D3 is more effective at raising vitamin D levels in your blood. Whichever option you decide on, try to take it with food—specifically, an item that contains fat. Because vitamin D is a fat-soluble nutrient, it “absorbs better that way,” Sara Velayati, MD, an obesity medicine specialist at Montefiore Einstein and an assistant professor at Albert Einstein College of Medicine in New York City, tells SELF. For this reason, Dr. Green makes a point of taking his supplements with breakfast or dinner. “The fattier and thicker the meal,” the better, he says.

Calcium

What it does: Calcium is a mineral that helps build and maintain strong bones and teeth. Women in their 40s approaching menopausal age should make it a particular priority to ensure their intake is adequate, Rachel Pessah-Pollack, MD, an endocrinologist at NYU Langone Health and a clinical professor at the NYU Grossman School of Medicine, tells SELF, as the physical changes that come with perimenopause and menopause can heighten bone loss and downstream health conditions like osteoporosis.

Who takes it: Like the other supplements on this list, calcium is best sourced from your diet, Dr. Pessah-Pollack says. “But if you’re not able to (I try to get dairy products but often come up short), a supplement is needed.” She takes a combined calcium and vitamin D tablet daily, as vitamin D helps calcium absorb.

How to take it: “The type of calcium supplements you are taking matters,” Dr. Pessah-Pollack says. Calcium carbonate and calcium citrate are the two most common. “Calcium carbonate should be taken with food because it requires gastric acid to be absorbed,” Dr. Pessah-Pollack says. Calcium citrate is an alternative that can be taken with or without food.

Magnesium

How it works: Magnesium is a mineral that can enhance sleep and muscle recovery. Research has also shown that it’s effective at preventing migraines, Raquel Zemtsov, MD, MPH, a family medicine doctor and assistant professor at the University of Pittsburgh School of Medicine, tells SELF.

Why some docs like it: In addition to Dr. Zemtsov, who takes magnesium to stave off migraine symptoms, Dr. Velayati takes magnesium for the sleep benefits. Likewise, Sheeva Talebian, MD, a reproductive endocrinologist at CCRM Fertility of New York, and Kathleen Jordan, MD, an internal medicine physician and chief medical officer at Midi Health, also turn to it at bedtime to boost their shut-eye.

What to keep in mind: Some types of magnesium are better tolerated, says Dr. Velayati—something to note if you’re especially sensitive to side effects. Magnesium glycinate “avoids the gastrointestinal upset caused by magnesium oxides and magnesium citrates,” for example, Dr. Jordan says. Depending on your needs, however, magnesium glycinate might not be the best option: Magnesium oxide is the recommended magnesium type for migraines, so that’s the one Dr. Zemtsov keeps on hand, for example. Taking magnesium with food can also help prevent GI distress, according to Dr. Velayati.

Omega-3s

How it works: Omega-3 fatty acids are polyunsaturated fats that are important for cardiovascular health. Common omega-3 supplements include fish oil and krill oil.

Why some docs like it: Dr. Jordan, Dr. Talebian, and Dr. Velayati all take omega-3s. “With their anti-inflammatory properties and association with improved brain health, this is a popular supplement among physicians, myself included,” Dr. Jordan, who takes krill oil, says. Similarly, Dr. Velayati dabbles in fish oil, but takes it selectively. “The right dose really depends on the goal, but I don’t think it’s necessary for everyone,” she says.

What to keep in mind: Fish oil supplements can have a characteristic fishy aftertaste, so it might take some trial and error to find one that works for you (read: doesn’t leave you gagging). What’s more, absorption and bioavailability can be a challenge, according to Dr. Jordan. Because omega-3s, like vitamin D, are fat-soluble, taking fish oil with a meal that contains fat can help skirt this problem. Some claim krill oil doesn’t cause the dreaded aftertaste as much as fish oil, and evidence suggests it’s also better absorbed by the body.

Iron

How it works: Iron, a mineral, acts as an essential ingredient in hemoglobin, a protein found in your red blood cells. Without enough iron, your blood won’t be able to carry out its core task of delivering oxygen to organs and tissues, resulting in anemia.

Why some docs like it: Iron deficiency is common in women due to the loss of blood during menstruation every month. “Occasionally, despite trying my hardest to seek out iron-rich foods, I still develop an iron deficiency,” Dr. Zemtsov says. When that happens, she takes ferrous gluconate (a particular type of iron supplement) every other day to treat or prevent anemia, since research shows iron supplements are better absorbed and cause fewer side effects that way. Dr. Jordan also takes iron supplements, citing the advantages for sleep, hair health, and overall energy.

What to keep in mind: Iron absorption is enhanced by vitamin C, so pairing your iron supplement with a food that contains vitamin C or even a vitamin C supplement—as Dr. Zemtsov does—can be helpful.

Fiber

How it works: Fiber, a type of carb, boosts digestion in a variety of ways: It keeps you full, helps prevent constipation, and supports bowel health. Besides the GI stuff, it also serves other functions in your body, including stabilizing your blood sugar and lowering “bad” LDL cholesterol.

Why some docs like it: “Unless you are that rare woman who regularly gets in her 25 to 30 grams per day, extra fiber intake is beneficial for almost everyone, and addresses multiple issues for me personally, including prediabetes and a rising cholesterol level,” Dr. Jordan says. She takes a fiber supplement as needed, on days when she doesn’t manage to hit her goal.

What to keep in mind: If your body isn’t acclimated to a high fiber intake, suddenly bombarding it could cause some digestive distress (think gas and bloating), so start slow to ease the transition. You’ll also need to increase your water intake simultaneously, since fiber requires water to work.

Selecting the right supplements

“When someone is considering a supplement, I usually recommend having a specific reason for taking it”—like a confirmed nutritional deficiency, Dr. Velayati says. “Overall, I view supplements as a way to fill a gap, not a substitute for good nutrition, sleep, exercise, and evidence-based medical care.” The bottom line: Supplements are really meant for plugging holes in your diet.

Here are a few final pointers:

Check with your own doc beforehand. “Always talk to your primary care physician before starting any new supplement to make sure it is safe for you,” Dr. Zemtsov says, especially if you take any other medications.
Don’t assume that “natural” translates to “safe.” Many supplements are marketed in this way, but it doesn’t necessarily have any bearing on their potential to cause for harm.
Choose reputable products when possible. While the FDA might not regulate supplements rigorously, some organizations offer third-party testing services. Dr. Zemtsov recommends looking for brands that have been tested and approved by US Pharmacopeia’s certifying organization or NSF International’s Certified for Sport program.
Don’t overdo it. If you’re trying to correct a nutrient deficiency with a supplement, be careful not to let the pendulum swing too far in the other direction. For example, too much calcium can increase the risk of kidney stones and cardiovascular issues, as can excessive vitamin D thanks to the aforementioned calcium absorption-enhancing effect.