Dietary supplements like vitamin C, multivitamins, or calcium supplements are touted for their benefits, but not everyone should be taking these nutritional supplements. Should you? The answer lies in your dietary habits.
Credit: Illustration: Bee Johnson

What if we told you that you could boost your health with a single pill? Of course you'd be excited. That's why Americans spent $36.7 billion on supplements in 2014, according to the National Institutes of Health.

Sadly, supplements aren't miracle workers. In some cases, there is no reliable evidence to back the disease-fighting, health-boosting claims that some of these products make. This has led to some strong oppositions to supplements in the medical community. "With two possible exceptions, fish oil and vitamin D, the healthy person has no business taking supplements," says internist Keith Roach, MD, associate professor of clinical medicine at Weill Cornell Medical College in New York City.

Credit: Illustration: Bee Johnson

But before you toss your tablets, consider that other health authorities, including the Harvard T.H. Chan School of Public Health, still advocate supplementing your diet with moderate amounts of vitamins and minerals, such as those found in a multivitamin.

Sometimes supplements are strongly advised. The Centers for Disease Control and Prevention recommend women who are pregnant or who could become pregnant take a daily supplement with 400mg of folic acid to prevent birth defects. Vitamin B12 supplements are recommended for people who cannot absorb enough of it from food, including many older adults, people who have had gastrointestinal surgery, and those with digestive disorders such as Crohn's or celiac disease.

Still, experts agree that with a few exceptions, the best way to get the nutrients you need is by eating real, healthy food. Admittedly, that's not always realistic, thanks to busy schedules resulting in less-than-perfect diets. Read on to find out whether your daily intake needs an extra boost.

Do You Really Need to Take These Popular Supplements?


Research suggests omega-3 fatty acids in cold-water fish (such as sardines, salmon, and tuna) can help stave off a host of conditions, including dementia and depression. And there's good evidence that people who regularly eat fatty fish have a lower risk of heart disease than people who don't. But "fish oil and fish are not the same thing," Roach says. The best evidence from large, epidemiological studies is based on fish consumption, not fish oil supplementation.

Eat fatty fish twice a week. "Two servings per week have been shown to have heart benefits, but people who eat a whole lot more generally don't get more benefit," Roach says. The exception: People who don't like fish should talk to their doctors about whether they should take a fish oil supplement.


THE SCIENCE These offer a range of micronutrients the body needs, and a study in the Journal of Nutrition found that many Americans do not get enough of them—in particular, vitamins A, C, D, and E, calcium, and magnesium. However, a growing body of evidence finds that multivitamins offer limited health benefits at best.

The exception? People who have absorption problems (such as seniors and people with Crohn's disese) or who have a very restricted diets might need to take a multivitamin.

As a way to found out a less-than-idea diet, multivitamins are generally considered to be a harmless, inexpensive option. Just don't expect to suddenly see changes in your overall health. The best way to boost nutrient intake: "Do your own cooking and eat whole foods," says internist Pieter Cohen, MD, an expert on the dietary supplement industry and an assistant professor at Harvard Medical School.

Credit: Illustration: Bee Johnson


THE SCIENCE Vitamin C is essential to help grow and repair tissues. Low levels, while rare, are associated with high blood pressure, stroke, and even some cancers. The most common reason people reach for vitamin C is to ward off a cold, but evidence doesn't support that theory. However, you probably won't do harm by exceeding the recommended daily allowance of 75mg. "In principle, you can get too much from supplements, but vitamin C is fairly innocuous, so the risks are low even then," says David Katz, MD, a nutrition expert and founding director of the Yale-Griffin Prevention Research Center.

Your body needs vitamin C to thrive. Katz suggests 1/2 cup of red bell pepper (95mg), 1 cup of broccoli (81mg), and a kiwi (64mg) as one way to get plenty of vitamin C—about as much as you'd find in a 250mg supplement.


You know you need calcium for strong bones, but did you know your body needs vitamin D to absorb it? Fortunately, your body makes it when exposed to bright sunlight. Alissa Rumsey, RD, of the Academy of Nutrition and Dietetics, suggests getting 15 to 20 minutes a day of sun. She recommends vitamin D supplements as well, especially in winter and in cold climates. You can also get some vitamin D from certain foods, such as fortified milk, egg yolks, and saltwater fish.