Epidemic influenza and vitamin D. Epidemiol Infect

Boston University, Boston, Massachusetts, United States
Epidemiology and Infection (Impact Factor: 2.49). 01/2007; 134(6):1129-40. DOI: 10.1017/S0950268806007175
Source: PubMed

ABSTRACT In 1981, R. Edgar Hope-Simpson proposed that a 'seasonal stimulus' intimately associated with solar radiation explained the remarkable seasonality of epidemic influenza. Solar radiation triggers robust seasonal vitamin D production in the skin; vitamin D deficiency is common in the winter, and activated vitamin D, 1,25(OH)2D, a steroid hormone, has profound effects on human immunity. 1,25(OH)2D acts as an immune system modulator, preventing excessive expression of inflammatory cytokines and increasing the 'oxidative burst' potential of macrophages. Perhaps most importantly, it dramatically stimulates 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. Volunteers inoculated with live attenuated influenza virus are more likely to develop fever and serological evidence of an immune response in the winter. Vitamin D deficiency predisposes children to respiratory infections. Ultraviolet radiation (either from artificial sources or from sunlight) reduces the incidence of viral respiratory infections, as does cod liver oil (which contains vitamin D). An interventional study showed that vitamin D reduces the incidence of respiratory infections in children. We conclude that vitamin D, or lack of it, may be Hope-Simpson's 'seasonal stimulus'.

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Available from: John C Umhau, Aug 21, 2015
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    • "Tuberculosis infection [40] and reactivation [41] were more likely in patients with low vitamin D; children with rickets were more likely to suffer from pneumonia [42]. An inverse relationship was reported between latitude (a surrogate for sunlight exposure, and thus for vitamin D availability) and influenza infections [43]. Supplementation with vitamin D and calcium decreased the risk in children for subsequent upper-respiratory infection [44]. "
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    Sleep Medicine Reviews 09/2013; 18(4). DOI:10.1016/j.smrv.2013.07.001 · 9.14 Impact Factor
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    • "However, the effects of 1,25(OH) 2 D 3 on macrophages remain incompletely characterized and have until now mainly been studied in the context of vitamin D deficiency and immune defense against infectious agents. As such, primary or monocyte-derived macrophages from vitamin D-deficient subjects are impaired in their ability to clear bacteria and viruses (Cannell et al. 2006; Schauber et al. 2007; Zasloff 2006). Also macrophages from mice with a disrupted VDR "
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    Immunobiology 08/2012; 217(12). DOI:10.1016/j.imbio.2012.07.018 · 3.18 Impact Factor
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    • "Evidence increases that vitamin D reduces the risk of incidence of and death from influenza and pneumonia. Cannell et al. (2006) "
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