Do kids really need vitamins? Here's what parents should know.

For decades, parents have urged kids to take a daily multivitamin — Flintstones Chewable, anyone? — to help fill nutritional gaps in their diet. Data shows that more than a third of kids in the U.S. take dietary supplements. While the American Academy of Pediatrics (AAP) doesn't recommend a daily multivitamin for children who eat a well-balanced diet, kids as a whole are notoriously picky eaters.

That raises a lot of questions for parents: Which kids can benefit from a vitamin? Do kids even need vitamins? And how can you choose the right option for your child if you go this route? Yahoo Life consulted five pediatricians for the answers to your pressing vitamin questions.

First, what's the difference between a vitamin and a supplement?

The terms are often used interchangeably, but they're not the same thing. "Vitamins are a type of supplement, but you can supplement nutrients that are not vitamins, such as fiber," Dr. Katie Lockwood, a pediatrician at Children's Hospital of Philadelphia, tells Yahoo Life.

There's also a difference in what the two can do, Dr. Kimberley Chien, a pediatric gastroenterologist at NewYork-Presbyterian Komansky Children's Hospital and Weill Cornell Medicine, says. "A vitamin is a substance that is essential for the body's normal function, growth and development," she says. "Supplements are substances that may aid or augment one's health but are not vital."

Should kids take multivitamins?

Again, the AAP doesn't recommend that kids who eat a well-balanced diet take a multivitamin, but pediatricians say they can be helpful for some children. "Specific populations may benefit from taking multivitamins, including those with restrictive diets — vegans, vegetarians, lactose-intolerant, gluten-free — very picky eaters, [those with] poor appetites and those with specific medical conditions," Dr. Tracy Zaslow, a pediatrician at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, tells Yahoo Life. "If your child falls into any of these categories, consider discussing the role of a multivitamin with their pediatrician, who can then direct and oversee a supplementation plan tailored to your child's specific needs."

The AAP does offer specific recommendations around some vitamins, though. The organization recommends that babies under the age of 12 months who are breastfed and have infant formula that isn't fortified with vitamin D take 400 IU (or 10 micrograms) of vitamin D daily. "The other example is an iron supplement for breastfed babies who are older than 4 months of age until they start consuming iron-rich complementary foods," says Dr. Lana Gagin, a pediatrician at Corewell Health Helen DeVos Children's Hospital. "In most other instances, healthy infants and children should be able to get recommended levels of vitamins and minerals from food alone. Well-balanced, nutrient-rich foods are the best source of all nutrients a child needs to grow healthy."

But vitamins can be helpful beyond babies, Dr. Robert Hamilton, a pediatrician at Providence Saint John's Health Center in Santa Monica, Calif., and host of the podcast The Hamilton Review: Where Kids and Culture Collide, tells Yahoo Life. "In general, kids are picky eaters," he says. "Some will only eat a few things. You try your best; they refuse. Vitamins provide a bit of a security blanket and insurance to make sure you're getting important nutrients into the child."

Should parents be concerned about dosing?

Parents should be aware of dosing instructions and follow them, Hamilton says. If your child takes an extra multivitamin, like a Flintstones vitamin, he says, they should be fine. "If they have a large number, like 30, you want to worry a bit," he says.

Ultimately, "it depends on the age of a child and the number of extra vitamins the child takes," Gagin says.

Zaslow also warns about overdosing. "There can be too much of a good thing," she says. "Iron and fat-soluble vitamins — A, D, E and K — can accumulate to dangerous levels when supplements are improperly taken."

If you think your child has accidentally overdosed on vitamins, Gagin recommends calling Poison Control at 800-222-1222 to get advice.

How do you know if your child could benefit from a supplement?

It's best to check with your child's doctor about this. "If a child has special nutrient needs or has inadequate daily intake, talk to your pediatrician about the need for vitamins and/or mineral supplements," Gagin says.

Your pediatrician will likely talk to you about your child's diet and may want to do bloodwork to see if your child is deficient in any essential nutrients and vitamins, Hamilton says.

Do vitamins boost immunity?

Having the right balance of vitamins and nutrients can help support a healthy immune system, Hamilton says, but taking immunity-specific vitamins usually isn't necessary. Chien agrees. "Immunity supplements may cause excess of vitamins or contain herbal supplements," she says. "Some children who may benefit from an immunity supplement are those who are picky eaters and/or don't get a balanced diet, especially if their diet is low in vitamin C, zinc or they are known to have vitamin D deficiency."

But Gagin says having your child eat well can do the same thing. "The best way to support immunity is by eating nutrient-dense foods that are rich in immune-boosting components such as vitamins D, C, E, zinc, pre- and probiotics, healthy fats and others," she says. "Also, make sure your child stays physically active and try to minimize psychological stress they might experience." Encouraging children to get the recommended amount of sleep a night for their age is also important, she says. "All of these components play an important role in keeping the immune system strong," Gagin adds.

How important is it to choose organic and 'clean' vegetable-based kids' vitamins?

That's more a choice for parents to make, says Hamilton, who recommends purchasing your child's vitamins from reputable brands. "There are a lot of vitamins on the market," he says. "You just want to avoid vitamins that are high in sugar." Some also may contain soy, peanuts, tree nuts and dairy, he adds. If your child has an issue with any of those ingredients, Hamilton says, you'll want to read the label closely.

Lockwood also stresses that supplements as a whole aren't FDA-regulated, making it tough to know if what a company says is in its vitamins is actually accurate.

Basically, if you're unsure about a vitamin, it's a good idea to check with your doctor.

Can a kid get addicted to vitamins?

If your child is taking vitamins with the recommended dosing, they should not become addicted to them, Hamilton says. "They can overdose — some chewable vitamins are tasty," he says. "But addiction? No."

Overall, doctors say that vitamins can be helpful for children — they just don't necessarily need them. "I recommend vitamins to almost all my patients," Hamilton says. "There are reasons to give kids vitamins, but you don't have to if your child is having a healthy diet."