According to WebMD, people can boost their immune systems by getting enough sleep, exercising regularly, eating healthy, managing stress, laughing and establishing better social networks. Everyday Health advises avoiding tobacco smoke and alcohol, and spending time in sunlight.
Everyday Health explains that sunlight is important because it leads to production of vitamin D. In summertime, 10 to 15 minutes of daily sunlight--with sunscreen--is sufficient. Other times of the year, sunlight may be too weak, and vitamin D supplements can help.
WebMD recommends getting seven to nine hours of sleep a night to keep stress hormones in balance. People should get at least 30 minutes of exercise a day because it helps stave off colds and releases hormones that induce positive emotions. Exercise often also leads to better sleep.
According to WebMD, consuming too many carbohydrates can lead to a decrease in immune system cells that destroy bacteria. A healthy diet that helps the immune system should focus on foods high in vitamins C and E, zinc and beta carotene. Brightly colored fruits and vegetables such as citrus, apple, kale, grapes and carrots are good. Stress hurts the immune system, so dealing with stress by slowing down, meditating and making friends also helps.