Vitamin D. According to some recent thinking, the “cold and flu season” may actually be the “Vitamin D deficiency season.” As the days grow shorter, people get less sunshine, leading to a decline in the body’s levels of this vitamin, which is essential to good health in many more ways than we used to think. Taking Vitamin D during the winter may therefore be one of the most effective ways to prevent colds and flu. Many researchers who’ve studied Vitamin D now recommend at least 1000 IU/day, but those with a known deficiency may be advised to supplement at even higher levels. There’s a simple test available to check for Vitamin D deficiency – ask your doctor.
Cold Away. This blend of Chinese herbs from Health Concerns is designed to “clear external heat and alleviate symptoms of the common cold.” A key component of this formula is the herb andrographis, which in several recent US studies was found to significantly decrease cold symptoms and the duration of a cold; it may also be useful for prevention. (NYBC stocks over 20 varieties of Traditional Chinese Medicine formulas, by the way.)
Vitamin C. Many good studies have shown a decrease in cold symptom duration, but no benefit for prevention. According to a guide to natural products published by the American Pharmacists’ Association in 2006, taking between one and three grams of Vitamin C per day may decrease cold symptoms (sore throat, fatigue, runny nose) by one to 1½ days.*
N-acetylcysteine (NAC) supports respiratory and immune system function. It has been studied extensively for chronic bronchitis. NAC is also the antidote for acetaminophen poisoning, now the leading cause of liver disease in the US. (Acetaminophen’s best-known tradename is Tylenol®, but it’s also found in many other drugs, so it’s become all too easy to overdose.)
One popular way to take NAC is to use PharmaNAC, notable for its careful quality control, pleasant “wildberry” flavor, and effervescent fizz!
Botanicals. In Traditional Chinese Medicine, astragalus is used for chronic respiratory infections, for colds and flu (both prevention and treatment) and for stress and fatigue. It contains complex sugar molecules called polysaccharides, which some studies show stimulate virus-fighting cells in the immune system. Researchers at the University of Texas and M.D. Anderson Cancer Center have turned up convincing evidence that astragalus boosts immune responses in lab animals, and in human cells in lab dishes.
Elderberry extract (as found in Jarrow Formulas’ Wellness Optimizer) and American ginseng (found in two Health Concerns formulas) are two other botanicals that have been studied for cold and flu symptoms in recent North American research, with some promising results. Also, a study conducted by Israeli scientists showed that elderberry extract suppressed the growth of influenza viruses in lab dishes. The same research team reported that patients given the extract recovered from the flu faster. The perennially popular echinacea, however, has generally disappointed in cold prevention studies, but is still touted by some as beneficial at the onset of a cold.
Probiotics. They say the best defense is a good offense, so consider upping your intake of the beneficial bacteria found naturally in such things as kefir (the lightly fermented milk beverage) and yogurt: they boost the flora in your intestinal tract, which is where an estimated 80% your immune system resides.
NYBC stocks eight varieties of probiotic supplements, ranging from Florastor capsules, a favorite of international travelers, to the 40 billion beneficial baceteria-per-capsule Ultra Jarro-Dophilus, to Green Vibrance, a powder added to fruit juice or another beverage of choice (complimentary shaker cup included!).
*Natural Products: A Case-Based Approach for Health Care Professionals, ed. Karen Shapiro. Washington, DC: American Pharmacists’ Assoc. (2006), “Cold and Flu,” pp. 173-192.