In a sequestered environment such as a classroom or dormitory, influenza can evoke concerns that are more than just casual. It has been noted by scientists and physicians that seasonal variations in ultraviolet radiation from the sun parallel the outbreak of the flu. The more obvious the sun’s activity, the less pronounced are viral infections. The converse is also true. Places at high latitudes do not receive enough sunlight to help the body produce vitamin D, known for its ability to cause an immune response to pathogens.
Studies performed in Norway, at the Institute for Cancer Research at Oslo University Hospital, in 2010, stated definitively that, “Seasonal variations in ultraviolet B (UVB) radiation cause seasonal variations in vitamin D status.” Immune response and seasonal influenza infection were directly related to vitamin D levels. This conclusion was drawn from weekly records that monitored the number of influenza cases and flu-related deaths in Sweden, Norway, the United States, Singapore, and Japan in light of concomitant changes in UVB strength. Results of this study indicated that, “…influenzas mostly occur in the winter season in temperate regions,” adding that, “…at high latitudes very little, if any, vitamin D is produced in the skin during the winter.” (Juzeniene. 2010)
Vitamin D deficiency is related to other matters besides the flu, including some cancers, heart disease, multiple sclerosis, diabetes, autism, and a host of others. (Cannell. 2008) This pro-hormone has been produced by life forms since the Creation, and is vital to the growth and development of the organism, from gestation to the grave. Of the common forms, D2 and D3, the latter is more biologically significant, since it is the one made by the skin in response to sunlight exposure. The supplement is usually derived from either lanolin or cod liver oil. This—D3— is the form that should be used to treat deficit. The former, D2, comes from fungal sources by activating ergosterol with UV light, and is not naturally present in humans. Synthetic, Rx forms are also available.
After being formed in the skin, vitamin D is converted into two different substances in the body. 25-hydroxyvitamin D (calcidiol) is the main storage form made by the liver. 1,25-dihydroxyvitamin D (calcitriol) is the most potent human steroid in the body, usually made in the kidneys. Calcitriol levels should not be used to determine vitamin D status.
Japanese research looked into seasonal flu among school children, from December 2008 to March 2009, and found that those who had not been taking vitamin D3 supplements were considerably more likely to get the flu than those who did supplement. Asthma sufferers experienced fewer exacerbations if they supplemented with the vitamin. (Urashima. 2010)
The sun has an eleven-year cycle during which its radiation level waxes or wanes. Discovered in the 1840’s by Samuel Schwabe, the cycle can change the amount of UVB light reaching the earth by as much as 400%, more than enough to influence vitamin D stores. The hypothesis that flu pandemics are associated with solar control of vitamin D levels has been developed and accepted. (Hayes. 2010) Part of this is based on vitamin D’s ability to help the body make an innate antimicrobial peptide called cathelicidin, which depends upon vitamin D levels of 40 - 70 nanograms per milliliter. (Cannell) European researchers believe that the economic burden of the flu on that continent could be reduced by 187 billion euros a year by supplementing with 2000-3000 IU of vitamin D a day. (Grant. 2009) Food fortification, artificial UVB, and, of course, supplements are practical options when the sun is unable to do what we expect.
MAIN ABSTRACT Int J Infect Dis. 2010 Dec;14(12):e1099-105. Epub 2010 Oct 29. The seasonality of pandemic and non-pandemic influenzas: the roles of solar radiation and vitamin D. Juzeniene A, Ma LW, Kwitniewski M, Polev GA, Lagunova Z, Dahlback A, Moan J.
Department of Radiation Biology, Institute for Cancer Research, the Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo, Norway. firstname.lastname@example.org
SUPPORTING ABSTRACTS Altern Med Rev. 2008 Mar;13(1):6-20. Use of vitamin D in clinical practice. Cannell JJ, Hollis BW.
Am J Clin Nutr. 2010 May;91(5):1255-60. Epub 2010 Mar 10. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H.
Medical Hypotheses. Volume 74, Issue 5, May 2010, Pages 831-834 Influenza pandemics, solar activity cycles, and vitamin D Daniel P. Hayes
Progress in Biophysics and Molecular Biology. 99(2-1); Feb-May 2009: 104-113 Estimated benefit of increased vitamin Dnext term status in reducing the economic burden of disease in western Europe William B. Grant, Heide S. Cross, Cedric F. Garland, et al
Journal of Clinical Virology Volume 50, Issue 3, March 2011, Pages 194-200 Vitamin D and the anti-viral state Jeremy A. Beard, Allison Bearden, and Rob Striker
Archives of Gerontology and Geriatrics Article in Press, Corrected Proof - Received 15 October 2010; revised 25 February 2011; accepted 28 February 2011. Available online 1 April 2011. Vitamin D: drug of the future. A new therapeutic approach N. Gueli, W. Verrusioa, A. Linguanti, F. Di Maio, A. Martinez, B. Marigliano and M. Cacciafesta
FASEB J. 2005 Jul;19(9):1067-77. Human cathelicidin antimicrobial peptide (CAMP) gene is a direct target of the vitamin D receptor and is strongly up-regulated in myeloid cells by 1,25-dihydroxyvitamin D3. Gombart AF, Borregaard N, Koeffler HP