Do they really need a children's vitamin?

Eating a healthy diet goes a long way towards preventing nutritional deficiencies, but how much do we really know about which nutrients kids are getting enough of in their everyday diets and which ones we need to supplement?

That's the question that researchers from institutions including Tufts University and the National Institutes of Health attempted to answer in a study published in the Journal of Pediatrics.

The study looked at the diets and supplement use of 7,250 children between 2 and 18 years old to see if taking supplements helped fill in nutritional gaps, or if it led to excess intake of certain nutrients in kids who already had good diets.

Following are the percentages of children who took dietary supplements:

• 23% of 2- to 8-year-olds
• 23% of 9- to 13-year-olds
• 26% of 14- to 18-year-olds

Here's what the study showed:

• Where diet worked: Most of the younger children got plenty of phosphorus, copper, selenium, folate, and vitamins B6 and B12 from diet alone.
• Where supplements helped: Dietary supplements helped fill in nutritional gaps (especially of magnesium, phosphorus, and vitamins A, C, and E) among older children. The prevalence of inadequate intake of all of the nutrients examined (except iron and phosphorus) was significantly lower among children who took supplements. There was a significantly higher prevalence of inadequate calcium and vitamins A, C, D, and E intake across all age groups among children who didn't take supplements. Most of the children between 2- and 8-years-old who didn't take supplements didn't meet the recommended intake for calcium and vitamins D and E.
• Where supplements didn't help: Even among children who did take supplements, more than one third didn't get enough calcium or vitamin D. Children who took supplements were more likely to have intakes above the tolerable upper intake level (UL) of iron, zinc, folic acid, and vitamins A and C. Younger children were also more likely to have intakes above the UL for copper and selenium.

Still wondering what to do?

The take-home message from this study is that younger children may be getting enough of most nutrients from diet alone, but may benefit from boosting intake of certain nutrients, like calcium and vitamins D and E. Older children might benefit from taking a multivitamin-mineral supplement, and making sure that they get enough calcium and vitamin D. "These findings may have implications for reformulating dietary supplements for children," the authors commented.

(J Pediatr 2012;doi:10.1016/j.jpeds.2012.05.009)