Wash them often -- especially before eating or after coughing or sneezing. Tell your child to scrub with soap or use alcohol-based hand gel. Also teach her to keep her hands away from her face so she won't transmit germs into her eyes, nose, or mouth, says pediatrician and Parents advisor Ari Brown, M.D.
Serve a variety of fruits, veggies, whole grains, dairy products, and other nutritious foods. If your child gets less than 400 IU of vitamin D daily from her diet, she should take a supplement. A vitamin D deficiency could increase the risk of many illnesses, including a cold and flu.
Well-rested children are less likely to get sick, so make a regular bedtime non-negotiable. A lack of sleep can disrupt the function of white blood cells called T cells, which play an important role in helping fight off infections.
Originally published in the November 2009 issue of Parents magazine.