8 Get enough vitamin D
Vitamin D is crucial to maintaining your immune system. In fact, the American Academy of Pediatrics recently doubled the amount of vitamin D it recommends for children to 400 IU. You can make sure your little one is getting her fill by giving her at least three servings per day of a calcium-loaded, vitamin D–rich food, such as calcium-fortified orange juice or milk. You should also make sure she gets outside to play whenever possible, even during the cold winter months, since the best source of vitamin D is still procured in the form of sunlight.
9 Boost vitamin C intake
While vitamin C has long been touted as a means of avoiding colds and flu, research also suggests it may prevent a case of the sniffles from developing into something more serious, like pneumonia. “During cold and flu season, I recommend kids take 250 milligrams of vitamin C in a nonacidic form, like Ester-C, so it doesn’t irritate their stomachs,” says Moyad.