
Catching a cold is not inevitable. Reducing stress, getting ample rest, and frequent handwashing all reduce the likelihood of infection. Limiting refined sugar helps keep white blood cells at their full infection-fighting strength. Even a few tablespoons of sugar, less than the amount found in a can of soda, may suppress the immune system for several hours. In addition to these preventative measures, a number of supplements can bolster the body's defenses against colds and flu.
A complex sugar found in many foods, beta glucan helps maintain healthy white blood cell function. A study in Surgical Gynecology and Obstetrics showed that supplementation with beta-glucan reduced pneumonia in trauma patients from 55% to 10%. A typical dosage range for beta-glucan is 100 mg to 200 mg per day.
Viruses can cause vitamin C levels to plummet. The Vitamin C Foundation recommends, at the onset of cold symptoms, taking eight grams of vitamin C every half hour until the stool becomes loose, usually within three to four hours. The Foundation suggests drinking lots of liquids to avoid dehydration, and continuing high doses of vitamin C for approximately one week, maintaining normal bowel function.
Vitamin E helps reduce infection, and is especially beneficial in the elderly.
This herb may reduce the duration and severity of colds.* In one German study of standardized echinacea extract, cold symptoms in the echinacea group subsided 33% sooner than in the placebo group.
Elderberry extract hinders virus reproduction, especially flu, and reduces the duration of symptoms.* The typical dose for immune enhancement is 1,000 mg to 2,000 mg per day of standardized elderberry extract.
In a study in the Annals of Internal Medicine, 50 adults with cold symptoms were randomly given a 12.8 mg zinc lozenge or a placebo, repeated every two to three hours during the cold. The zinc group recovered in an average of 4.5 days compared with eight days for the placebo group.