About half of all young children (and 30 percent of teens) have taken dietary supplements, according to a 2004 study in Pediatric Annals. But scientists aren't so sure it's necessary.
"In general, the data regarding the benefits of taking vitamins is weak," said biochemist Thomas Sherman, a neuroendocrinologist and an associate professor at Georgetown University School of Medicine. "And the data for children is pretty much nonexistent."
What researchers do know is that most kids can get the nutrients they need from a healthful diet alone. Thanks to fortified milks, cereals and other foods, even children with less-than-ideal diets will still be okay, said William "Biff" Rees, head of the Virginia chapter of the American Academy of Pediatrics.
"I've been in practice a long time," said Rees, who has been seeing families in Northern Virginia for 37 years, "and I can't remember seeing a vitamin-deficient child who didn't have some sort of illness underlying the deficiency. It's really hard to get vitamin-deficient — you almost have to work at it."
So if your child is healthy, the bottom line seems to be that you don't need to worry about a daily multivitamin or, for the most part, individual ones. Both Sherman and Rees recommend getting children the vitamins they need by focusing on food instead. Well-balanced meals with plenty of fruit and vegetables will provide kids with most of the vitamins and minerals they need for good health, along with great eating habits for the rest of their lives.
But there are a few exceptions where food alone won't do the trick. The big one is vitamin D, which is critical for building strong bones and may protect against cancer and some other diseases. Very few foods naturally have high levels of vitamin D. Our bodies produce most of the vitamin D we need through exposure to sunlight — or at least they are supposed to.
Although researchers disagree over how much vitamin D we need — the Institute of Medicine recommends 400 to 800 international units a day, but some experts call for as many as 5,000 IUs — they know that many of us don't get enough. That means kids, too: A 2008 study found about 40 percent of children have inadequate or less than optimal levels.
"We treat the sun like a death star, particularly when it comes to our kids," Sherman said. "We slather on the sunscreen, we put on hats and long sleeves and even put shades on strollers, so we're all chronically deficient in vitamin D."
That's why many experts recommend vitamin D supplements for kids of all ages. Breast-fed babies especially should get that extra vitamin D, because breast milk tends to have lower vitamin D levels than fortified formulas do.
If your child has to follow a special diet or has special nutritional requirements, it may be worth considering other supplements. Kids who don't eat meat or dairy products, for example, can miss out on key nutrients. "Vegetarian kids you can raise without supplements if you're careful," said Rees. "Vegan is difficult but not impossible to do."
The risk with meat- or dairy-free diets is that your child may not be getting enough iron, calcium or B vitamins. Rees suggests working with your pediatrician to monitor your child's diet and vitamin and mineral intake, adding supplements if there are concerns.
Medical conditions (such as cystic fibrosis) that limit how well a person can absorb vitamins from food may also make supplements important. In all cases, parents should ask their pediatricians what's needed.
Sherman and his wife decided to give their three children vitamin D supplements and let healthful meals do the rest. But he says he understands wanting to use supplements as insurance.
"Whatever you decide, it's not a choice you should have a tremendous amount of angst about," Sherman said. "It isn't a life-or-death choice, and if it gives you one less thing to worry about, then go for it."