The relationship between vitamin D status and the strength of the immune system is a hot topic. Actually a steroid hormone more than a vitamin, vitamin D is made by the skin after exposure to the ultraviolet radiation of the sun. Because the sun’s angle of incidence outside the tropics is considerably lower in winter, the skin’s response is too weak to manufacture sufficient stores of this vital nutrient.
In the early 1980’s, British physician R. Edgar Hope-Simpson proposed a relationship between solar radiation and the seasonality of influenza. Without sufficient sunlight, the skin does not produce vitamin D, deficiency of which is common in winter. This steroid hormone has considerable influence on immunity, where it prevents excessive expression of inflammation and is able to, “…stimulate the expression of potent anti-microbial peptides, which exist in neutrophils, monocytes, natural killer cells, and in epithelial cells lining the respiratory tract where they play a major role in protecting the lung from infection.” (Cannell. 2006) This study, performed at California’s Atascadero State Hospital, states that deficiency of vitamin D predisposes children to respiratory infections. UV radiation, either natural or artificial, increases vitamin D levels and thereby reduces the incidence of pulmonary infections.
Vitamin D deficiency has been associated with many of the diseases of modern society, but traditional medicine has been reluctant to address this concern, or even to recognize it. This vitamin is the only known precursor to a potent steroid hormone that is able to regulate expression in a number of tissues. It does not exist in appreciable amounts in the diet, not even in fortified foods like dairy. People used to make enormous amounts of vitamin D until they were warned to stay out of the sun. If not exposed to the sun, we need to get it from supplements. The flu epidemic of 1918 took a great toll. Autopsies on some of the fifty million people who died revealed destruction of the respiratory tract. This is the inflammation that vitamin D has been found to prevent.
Randomized, double-blind, placebo-controlled studies done in Japan in 2010 found that vitamin D3 supplementation not only reduced incidence of influenza type A, but also reduced asthma attacks as a secondary outcome. (Urashima. 2010). The elderly tend to have suboptimal levels of vitamin D, which is associated with an increased risk of falls as well as seasonal virus attacks. Vitamin D supplementation in this group is a realistic intervention that can pay large dividends. 2000 IU a day has been suggested as a minimal dose also to help prevent osteoporosis, increased risk of certain cancers, aberrant glucose and lipid metabolism and to improve quality of life. (Lawless. 2011) (Cherniak. 2008). Solar activities of the sun have a cycle of about eleven years, and an interesting phenomenon is that flu epidemics seems to follow the pattern. (Hayes. 2010).
Vitamin D is not the sole player in the winterizing game. Viruses need to get into your cells to make copies of themselves, using your cellular materials. Replication of the flu virus is interrupted by a standardized elderberry extract called Sambucol, the use of which brought improvement to more than 90% of the persons in a study group within two days. Since there is no satisfactory medication to cure the flu, this natural substance is nearly miraculous because it’s also inexpensive, has no side effects, and works on both A and B strains of influenza. (Zakay-Rones. 1995) (Zakay-Rones. 2004). The anti-viral properties of elderberry are attributed to its flavonoids content, some of which are peculiar to that plant alone. (Roschek. 2009).
A considerable part of the immune system resides in the gut, where intestinal microflora work to maintain the status quo. Keeping those bacteria happy and healthy makes sense, so probiotics have been examined as a support system. In a controlled study in Wisconsin, scientists found that six months of supplementation with a probiotic resulted in reduced fever, runny nose, and cough incidence in youngsters aged 3 to 5 years. Duration of prescription medications and missed school days also were reduced. (Leyer. 2009) Day care centers across the Atlantic also fared well in the reduction of childhood infections with probiotic use. In Finland, researchers saw a substantial reduction in respiratory infections and their severity among children under 6 years old, accompanied by a reduction in the need for antibiotic treatment in those who received probiotic dairy products. (Hatakka. 2001)
Investigations of echinacea as treatment for flu were not as positive as those for prevention. It was discovered that early intervention, at the fist symptoms, brought the best results using an echinacea compound tea, namely one called Echinacea Plus. (Lindenmuth. 2000). Because there are too many variables, including the part or parts of the plant used, the brewing times and techniques, the variety of the plant used, its cultivation conditions, and other factors, test results are likely to differ. Even in trials with sound methodology, results may conflict. (Melchart. 2000) (Linde. 2006) Using echinacea as prevention or as treatment, then, may be an uncertain proposition.
There is more to consider. Garlic and onions have putative anti-bacterial and anti-viral properties. (Goncagul. 2010). (Harris. 2001) Exercise, regardless of intensity or duration, and sound sleep of uninterrupted duration help the lymphatic system to clear impurities and to boost immunity. One or all of these suggestions might be your ounce of prevention. Oh, yeah, one last thing. The higher the humidity in your house in the winter, the less likely viruses are to be transmitted. (Lowen,. 2007) (Yang. 2011)
Cannell JJ, Vieth R, Umhau JC, Holick MF, Grant WB, Madronich S, Garland CF, Giovannucci E. Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec;134(6):1129-40.
Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H.
Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren.
Am J Clin Nutr. 2010 May;91(5):1255-60. Epub 2010 Mar 10.
Lawless S, White P, Murdoch P, Leitch S.
(Preventing) two birds with one stone: improving vitamin D levels in the elderly.
J Prim Health Care. 2011 Jun 1;3(2):150-2.
Cherniack EP, Levis S, Troen BR.
Hypovitaminosis D: a widespread epidemic.
Geriatrics. 2008 Apr;63(4):24-30.
Influenza pandemics, solar activity cycles, and vitamin D.
Med Hypotheses. 2010 May;74(5):831-4. Epub 2009 Dec 28.
Zakay-Rones Z, Varsano N, Zlotnik M, Manor O, Regev L, Schlesinger M, Mumcuoglu M.
Inhibition of several strains of influenza virus in vitro and reduction of symptoms by an elderberry extract (Sambucus nigra L.) during an outbreak of influenza B Panama.
J Altern Complement Med. 1995 Winter;1(4):361-9.
Zakay-Rones Z, Thom E, Wollan T, Wadstein J.
Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections.
J Int Med Res. 2004 Mar-Apr;32(2):132-40.
Roschek B Jr, Fink RC, McMichael MD, Li D, Alberte RS.
Elderberry flavonoids bind to and prevent H1N1 infection in vitro.
Phytochemistry. 2009 Jul;70(10):1255-61.
Leyer GJ, Li S, Mubasher ME, Reifer C, Ouwehand AC
Probiotic effects on cold and influenza-like symptom incidence and duration in children.
Pediatrics. 2009 Aug;124(2):e172-9.
Hatakka K, Savilahti E, Pönkä A, Meurman JH, Poussa T, Näse L, Saxelin M, Korpela R.
Effect of long term consumption of probiotic milk on infections in children attending day care centres: double blind, randomised trial.
BMJ. 2001 Jun 2;322(7298):1327
Brinkeborn RM, Shah DV, Degenring FH.
Echinaforce and other Echinacea fresh plant preparations in the treatment of the common cold. A randomized, placebo controlled, double-blind clinical trial.
Phytomedicine. 1999 Mar;6(1):1-6.
Lindenmuth GF, Lindenmuth EB
The efficacy of echinacea compound herbal tea preparation on the severity and duration of upper respiratory and flu symptoms: a randomized, double-blind placebo-controlled study.
J Altern Complement Med. 2000 Aug;6(4):327-34.
Melchart D, Linde K, Fischer P, Kaesmayr J.
Echinacea for preventing and treating the common cold.
Cochrane Database Syst Rev. 2000;(2):CD000530.
Linde K, Barrett B, Wölkart K, Bauer R, Melchart D.
Echinacea for preventing and treating the common cold.
Cochrane Database Syst Rev. 2006 Jan 25;(1):CD000530.
Goncagul G, Ayaz E.
Antimicrobial effect of garlic (Allium sativum).
Recent Pat Antiinfect Drug Discov. 2010 Jan;5(1):91-3.
Harris JC, Cottrell SL, Plummer S, Lloyd D.
Antimicrobial properties of Allium sativum (garlic).
Appl Microbiol Biotechnol. 2001 Oct;57(3):282-6.
Lowen AC, Mubareka S, Steel J, Palese P.
Influenza virus transmission is dependent on relative humidity and temperature.
PLoS Pathog. 2007 Oct 19;3(10):1470-6.
Wan Yang, Linsey C. Marr
Dynamics of Airborne Influenza A Viruses Indoors and Dependence on Humidity
PLoS ONE: Research Article, published 24 Jun 2011 10.1371/journal.pone.0021481
*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.