AsthmaHow does vitamin D work?

Vitamin D may reduce the risk of asthma exacerbations by limiting the risk of viral infections, in part by inducing production of cathelicidin and defensins1 2 3 4 5 6 7 8.

However, vitamin D also shifts the Th1-Th2 balance toward Th29, thus potentially increasing the risk of asthma exacerbations10

As a result, high vitamin D doses are not recommended for those with asthma9. However, because vitamin D also enhances production of IL-1011 12 13 14, which reduces the risk of asthma attacks, this effect may trump shifting of the Th1-Th2 balance towards Th2.

Page last edited: 09 May 2011


  1. Cannell, J. J. Vieth, R. Umhau, J. C. Holick, M. F. Grant, W. B. Madronich, S. Garland, C. F. Giovannucci, E. Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec; 134 (6): 1129-40.
  2. Cannell, J. J. Zasloff, M. Garland, C. F. Scragg, R. Giovannucci, E. On the epidemiology of influenza. Virol J. 2008; 529.
  3. Ginde, A. A. Mansbach, J. M. Camargo, C. A., Jr. Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2009 Feb 23; 169 (4): 384-90.
  4. Ginde, A. A. Mansbach, J. M. Camargo, C. A., Jr. Vitamin D, respiratory infections, and asthma. Curr Allergy Asthma Rep. 2009 Jan; 9 (1): 81-7.
  5. Mansbach, J. M. Camargo, C. A., Jr. Respiratory viruses in bronchiolitis and their link to recurrent wheezing and asthma. Clin Lab Med. 2009 Dec; 29 (4): 741-55.
  6. Sabetta, J. R. DePetrillo, P. Cipriani, R. J. Smardin, J. Burns, L. A. Landry, M. L. Serum 25-hydroxyvitamin d and the incidence of acute viral respiratory tract infections in healthy adults. PLoS One. 2010; 5 (6): e11088.
  7. 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.
  8. Gombart AF. The vitamin D-antimicrobial peptide pathway and its role in protection against infection. Future Microbiol. 2009 Nov; 4 (9): 1151-65.
  9. Kuo, Y. T. Kuo, C. H. Lam, K. P. Chu, Y. T. Wang, W. L. Huang, C. H. Hung, C. H. Effects of vitamin D3 on expression of tumor necrosis factor-alpha and chemokines by monocytes. J Food Sci. 2010 Aug 1; 75 (6): H200-4.
  10. Wegmann, M. Th2 cells as targets for therapeutic intervention in allergic bronchial asthma. Expert Rev Mol Diagn. 2009 Jan; 9 (1): 85-100.
  11. Bosse, Y. Lemire, M. Poon, A. H. Daley, D. He, J. Q. Sandford, A. White, J. H. James, A. L. Musk, A. W. Palmer, L. J. Raby, B. A. Weiss, S. T. Kozyrskyj, A. L. Becker, A. Hudson, T. J. Laprise, C. Asthma and genes encoding components of the vitamin D pathway. Respir Res. 2009; 1098.
  12. Dimeloe, S. Nanzer, A. Ryanna, K. Hawrylowicz, C. Regulatory T cells, inflammation and the allergic response-The role of glucocorticoids and Vitamin D. J Steroid Biochem Mol Biol. 2010 May 31; 120 (2-3): 86-95.
  13. Sandhu, M. S. Casale, T. B. The role of vitamin D in asthma. Ann Allergy Asthma Immunol. 2010 Sep; 105 (3): 191-9; quiz 200-2, 217.
  14. Searing, D. A. Leung, D. Y. Vitamin D in atopic dermatitis, asthma and allergic diseases. Immunol Allergy Clin North Am. 2010 Aug; 30 (3): 397-409.