You’ve heard about the health-bolstering powers of things like vitamin C, vitamin D, and calcium (and, if you grew up in the '90s, were likely fed a chalky Flintstones vitamin along with your Corn Flakes). Your body needs vitamins; there’s no doubt about that. But do you need to take vitamins and other supplements? That depends.

Americans are definitely on the vitamin bandwagon: More than half of us take at least one supplement. But most of us probably don’t need them, researchers say. “It’s possible to get all of the nutrients you need by eating a variety of healthy foods,” registered dietitian Carol Haggans told the National Institutes of Health's newsletter in 2013.

Speaking broadly, she’s right. Your body is better able to absorb nutrients from food than it is from pills, and a balanced diet can provide most people with all the vitamins and minerals they need. But there are exceptions:

  • People with dietary restrictions: Maybe you’re a vegan for philosophical reasons, or you’re lactose intolerant, or you have celiac disease. Cutting out any large food group can create nutrient deficiencies if you’re not careful to fill in the gaps.
  • Women who are pregnant or want to become pregnant: Prenatal vitamins are specially formulated with high levels of iron and folic acid to support a healthy pregnancy.
  • People who have absorption issues: Some people’s bodies just can’t take in all the nutrients they need from food. If blood tests show low nutrient levels, you may benefit from supplements.

That list of exceptions used to include older women, who need more calcium than men and younger people. But recent studies have cast some doubt on the wisdom of universally recommending calcium supplements. Like any vitamin or mineral, calcium in high doses can start more problems than it solves.

So do you, personally, need to take vitamins? There are only two people who can answer that: you and your doctor. Call your physician before starting or stopping any supplement (even those marketed as “natural”) to be sure it’s a safe choice for you.