By Korin Miller – Self
While experts agree that multivitamins aren’t needed for most Americans, there’s been a lot of talk about vitamins lately. Enough to make one wonder: Is taking vitamins good for you, ever? Gwyneth Paltrow’s doctor Alejandro Junger, M.D., for example, recently said supplements helped the actress and Goop founder rebound from adrenal fatigue, a nonmedically recognized condition that some say is marked by fatigue, issues with concentrating, and difficulty handling stress. Last week, TV personality Lo Bosworth claimed on her blog that vitamins improved her depression, which was brought on by “severe deficiencies” of vitamin B12 and vitamin D. And Khloe Kardashian recently posted a photo of her vitamin regimen on Instagram—and based on the photo, it appears that she takes 23 vitamins a day.
These celebrities are just a small sample of a larger trend. Americans spend $30 billion a year on supplements, according to The Journal of Nutrition. But is everyone wasting their money, or is there a time when taking vitamins is actually good for you?
Recent research on vitamins hasn’t exactly supported the prevailing idea that everyone should be taking multivitamins. A 2013 large-scale scientific review published in the Annals of Internal Medicine found that there was “no clear evidence” that vitamins helped increase a person’s life span or decrease their odds of developing heart disease or cancer. That same year, the United States Preventive Services Task Force, a group of doctors who give out medical advice based on scientific evidence, did not find enough evidence to recommend for or against the use of multivitamins to prevent heart disease or cancer in people who aren’t deficient in certain nutrients. “The current evidence is insufficient to assess the balance of benefits and harms of the use of multivitamins for the prevention of cardiovascular disease or cancer,” the organization said.
It’s not just lack of effectiveness that should determine whether you shell out for supplements. Some vitamins might not even contain the ingredients that they claim on the bottle. In 2015, the New York State attorney general’s office conducted a study on supplements sold at Target, Walmart, Walgreens, and GNC, and found that about four out of five of those tested didn’t contain the herbs they were supposed to. Instead, they included filler ingredients like rice, beans, pine, citrus, asparagus, wheat, and wild carrots.
Also, important to note: Vitamin and supplement claims do not have to be approved by the Food and Drug Administration, and the amount of studies done on any particular type of supplement varies widely. Many health benefit claims made by supplement manufacturers haven’t been evaluated through peer research, while others—especially non-vitamin, non-mineral supplements like those containing herbs—haven’t been proven to be effective in clinical trials.
With all of this in mind—plus the fact that you can get all the nutrients you need from a balanced, plant-filled diet—you may be wondering: Is it ever a good idea to invest in vitamin supplements? Here’s what you need to know.
Vitamin supplements are useful for people with certain vitamin deficiencies and for women who are pregnant or breastfeeding.
You’ve probably heard at some point that it’s important to take folic acid before you become pregnant and during pregnancy, and there’s research to back that up. The Centers for Disease Control and Prevention (CDC) points to evidence that finds that taking folic acid before getting pregnant and in early pregnancy lowers the risk of having a baby with neural tube defects (i.e., birth defects of the brain, spine, or spinal cord). That’s why the CDC recommends that all women who can get pregnant should take 400 micrograms of folic acid daily.
Women are encouraged to take prenatal vitamins (which contain folic acid) when they’re pregnant, and that recommendation extends to breastfeeding moms—with good reason, Rebekah L., Huppert, R.N., I.B.C.L.C., a lactation consultant at the Mayo Clinic, tells SELF. “Most of the vitamins and minerals we need are in food, and a healthy diet will likely get you close, but while you’re breastfeeding, taking a multivitamin can be your insurance policy,” she says. Most of the vitamins that a growing baby needs will be in the mother’s breast milk, but breastfeeding can deplete the mom’s own vitamin stores, Huppert explains. Iron may also be important for a woman to take after she delivers, since blood loss is common during the birthing process (the mineral can boost hemoglobin, which helps transport oxygen in the blood).
If you suffer from a vitamin deficiency, it can be helpful to take a supplement of that particular vitamin, Dana Simpler, M.D., a primary care practitioner at Baltimore’s Mercy Medical Center, tells SELF. For example, “Many adults can develop a B12 deficiency—especially if they follow a plant-based diet—that can be detected in a blood test,” she says.
Vitamin D is a vitamin that can be “notoriously difficult” to find in a healthful diet, Gina Keatley, a C.D.N. practicing in New York City, tells SELF. While she points out that people can get more vitamin D from eating tuna, salmon, nuts, and seeds, some may need to take a supplement to get the right amount. This is especially true if you don’t get enough sun exposure throughout the day as well, since the UV rays in sunlight helps our bodies produce this vitamin. Some studies suggest a link between low vitamin D levels in the blood and mood disorders like depression and seasonal affective disorder (SAD), the Mayo Clinic says, but more research is needed before a conclusion can be made.
If you suffer from a medical condition like anemia, a red blood cell deficiency that causes fatigue, taking an iron supplement may be necessary, women’s health expert Jennifer Wider, M.D., tells SELF. Other medical conditions and medications can impact a person’s absorption of particular nutrients, and supplementation might be needed to keep you healthy, Sonya Angelone, R.D., a spokeswoman for the Academy of Nutrition and Dietetics, tells SELF.
However, you should never take vitamin supplements without first determining with your doctor if you have a deficiency.
If you do have a vitamin deficiency, taking a supplement will help get you back on track. But experts agree that it’s generally a bad idea to start taking a new supplement based on a self-diagnosis. “Take a supplement only if you need it,” Angelone says. “The dose depends on several factors, including the levels in your own body.”
And, while it seems like a good idea to take a multivitamin just in case, Dr. Simpler points out that recent evidence really doesn’t imply that it’s necessary or good for you. “I used to recommend them and take them myself, but it’s now quite clear that there’s no need for multivitamins in an otherwise healthy person with a good diet,” she says. “It’s not for somebody that has normal access to food.”
While taking too many vitamin supplements may seem harmless, it actually can be dangerous.
Fat-soluble vitamins—A, D, E, and K—build up in your body for long periods of time, Angelone says, so you want to make sure you actually need them before you take them. Having too much vitamin A in your body can be bad for your bones, Dr. Wider points out, and too much vitamin E may potentially increase the risk of heart problems in certain people. “If a person takes too much of these, the consequences can be serious,” she says.
Water-soluble vitamins—i.e., those that dissolve in water—like the B vitamins (folate, thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B6, and vitamin B12) and vitamin C can all be flushed out of your body with water, Dr. Wider says, so your body can’t store excess amounts of them. “But there are some potential dangers with these, too,” she says. For example, taking too much vitamin C and not drinking enough water can cause diarrhea and nausea. Those prone to kidney stones should also pass on vitamin C, because it can increase stones in people predisposed to them. And there’s a limit to how much B6, a vitamin considered good for pregnant and nursing moms that appears in many prenatal vitamins, women should take. “Levels higher than 80 mg can cause neurological, GI, and skin problems,” Huppert says. (Since B6 also shows up in energy drinks, nursing moms on prenatal vitamins are discouraged from drinking energy drinks, she points out.)
And, while some people can benefit from a vitamin D supplement, you shouldn’t just start taking high levels of the vitamin in hopes of warding off depression. “Excess vitamin D can be just as harmful as a deficiency,” says certified dietitian-nutritionist Lisa Moskovitz, R.D., CEO of NY Nutrition Group. She says that’s why it’s best to have tests run by your doctor and see what your D levels are before jumping on any new supplement. “Too much of a good thing is not a good thing at all,” she adds.
Moskovitz tells SELF that it’s also important to be wary of drug interactions. “Taking too many of certain vitamins can be dangerous as they interfere with medications and medical conditions, and can cause toxicity,” she says. For example, calcium supplements can interfere with thyroid medications, says Moskovitz. Keatley also points out that vitamin K could be deadly if you’re taking certain medications, such as the blood thinner Warfarin.
Here’s the bottom line.
If you suspect that you have a vitamin deficiency, talk to your doctor about getting blood work done to see if you’re low in any particular nutrient. From there, your doctor may recommend eating more of particular foods or taking a supplement—but it’s important to have that conversation before popping a new pill. And always be sure to let your doctor know about any other kinds of supplements you’re taking, in case of drug interactions. “Always speak with your health care provider,” Dr. Wider says. “It’s a safer way to go.”
CORRECTION: A previous version of this article stated that the United States Preventive Services Task Force “chose not to recommend” the use of multivitamins to help prevent heart disease or cancer. We have since corrected this sentence to clarify that the task force concluded there was insufficient evidence to make a recommendation for or against the use of multivitamins in these cases.