Dietary supplements include vitamins, fish oil, herbs, minerals like calcium, and more. And if you take one, you’re not alone. About half of U.S. adults do. But should you?

That’s a question for your doctor or dietitian, says Linda Van Horn, a professor of preventive medicine at Northwestern University.

“I get some concern when I see people take one of these and one of those, just because they’ve read somewhere that a supplement is helpful,” Van Horn says. “Imbalances can easily occur, and you may not be aware of it.”  

Food is the best way to get your vitamins and minerals. But it sometimes can be hard to eat enough fresh veggies, fruits, whole grains, and other healthy options. A multivitamin can be a safe way to boost your nutrients.

Do You Need a Supplement?

Most healthy people don’t need one. But some folks may need extra help, says Jerlyn Jones, a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics. Reasons include if you’re elderly, take certain medicines, or don’t have easy access to healthy food because of income or where you live.

Talk to your doctor if you:

Are or might get pregnant. You may not get enough iron from food, especially if you get morning sickness. And all women who are pregnant, or trying to be, should take folic acid. Prenatal vitamins give you “an extra cushion of safety,” says Van Horn.

Care for a young child. Infants and children may need help getting vitamin D and iron.

Eat a restricted or limited diet. It’s harder to get some nutrients, like vitamin B12 or calcium, if you leave out certain food groups. That may happen if you’re vegan or have a dairy allergy.

Are older than 50. Your body starts to absorb less of vitamins D and B12 as you get older. After you reach middle age, you may need to take extra steps to get enough.

Had gastric bypass surgery. Your gut may not absorb nutrients as well.

Have certain genetic or health conditions. You may have trouble absorbing nutrients if you have:

  • Inflammatory bowel disease (like ulcerative colitis or Crohn’s)
  • Celiac disease
  • Cystic fibrosis
  • Liver disease
  • Cancer
  • An autoimmune disorder (like pernicious anemia)
  • Alcohol dependence 
  • A mutation in certain genes
  • Darker skin (you may absorb less vitamin D)