With two little kids in daycare, I’m going to do everything I can to keep myself—and indirectly, the little guys, too, I hope—from getting sick. I’ll be getting a flu shot, washing my hands, staying away from the “to-share” treats co-workers put out and doing my best to keep my distance from anyone who is coughing, sneezing or sniffling—or who has obvious green snot dripping from his nose. (Again, my kids are in daycare.)
Thanks to Emily Sohn, who, in the September/October 2010 issue of EatingWell, shares strategies to boost immunity naturally , I have three more stay-well tactics to try.
Fill Your Vitamin D Tank.
Your body makes vitamin D from sunlight. You can also get it—albeit in smaller doses—from fatty fish, such as salmon, and fortified milk. But since the majority of Americans don’t get enough vitamin D, most experts recommend a D supplement. In a study published recently in the American Journal of Clinical Nutrition, children who took daily vitamin D supplements (1,200 IU) were 40 percent less likely to get a common flu virus than kids who took a placebo. Laboratory studies indicate that the nutrient may help immune cells identify and destroy bacteria and viruses that make us sick, says Adit Ginde, M.D., M.P.H., a public health researcher at the University of Colorado School of Medicine in Denver. Aim to get at least 1,000 IU of vitamin D daily (check with your doctor before taking more). Get more vitamin D with these healthy recipes. 
Get a Daily Dose of Soluble Fiber.
Mice that ate a diet rich in soluble fiber for six weeks recovered from a bacterial infection in half the time it took mice that chowed on meals containing mixed fiber, according to a recent study in the journal Brain, Behavior and Immunity. Soluble fiber—abundant in citrus fruits, apples, carrots, beans and oats—helps fight inflammation, says lead author Christina Sherry, Ph.D., R.D., of the University of Michigan, Ann Arbor. Insoluble fiber—found in wheat, whole grains, nuts and green leafy vegetables—is still important for overall health, but it doesn’t seem to have the same impact on immunity. Strive for 25 to 38 grams of total fiber a day, Sherry says, paying extra attention to getting the soluble kind.
Related: High-Fiber Breakfasts You Can Grab & Go 
Overweight adults who cut their daily calorie intake by nearly a third saw a 50 percent boost in immunity, according to a six-month study out of Tufts University. (Those who cut calories by 10 percent had smaller improvements.) Restricting calories may reduce levels of compounds in the body that depress your immune response, says Tufts nutritional immunologist Simin Meydani, D.V.M., Ph.D. Animal studies suggest that calorie restriction could work in normal-weight individuals too. “Try to maintain your body weight at what is considered ideal,” Meydani says, because eating more than what you need drags the immune system down. (Need help losing weight? See what a 1,500-calorie day looks like! ) And remember: when you cut back on quantity, you need to be even more vigilant about the quality of your diet. Aim to eat more fruits and vegetables—and choose lean protein sources, such as fish, chicken and low-fat dairy.
What foods do you think help keep you from getting sick? Tell us what you think below.