While we try to make sure our kids are getting enough nutrition—calcium from milk and dairy, B complex from fortified cereals, vitamin C from citrus and so on—we sometimes feel we need an insurance plan in the form of children’s vitamin supplements. But are they really necessary? Surprisingly, the estimated one third of U.S. kids who take a vitamin or mineral supplement are probably the least likely to need them, according to a new study from the University of California–Davis children’s hospital. Those children are usually the ones who are already getting the right nutrients from a healthy, balanced diet of foods like fruits, veggies, proteins, whole grains and low-fat milk. The children who could potentially benefit from a supplement (but are less likely to take one, according to the study) are those who don’t eat enough of a variety of healthy foods. So if your child is a picky eater who lives on chicken nuggets and thinks anything green is grass, talk to his doctor about the benefits of vitamin supplements.