For optimal protection against influenza, people may want to consider both vitamin D and vaccination.
Two randomized controlled trials for vitamin D supplementation and incidence of influenza have been reported.
No effect of vitamin D was found for type B influenza1, which is generally less common than type A influenza.
Because vitamin D impacts both the function of the adaptive and innate arms of the immune system, an adequate level of circulating 25(OH)D is essential for allowing a balanced and optimal response by the immune system toward infection. Inadequate levels will likely lead to an imbalanced immune response that is detrimental to the afflicted individual.
Vaccination strengthens the body’s adaptive immune response, so for optimal protection against influenza, people may want to consider both vitamin D and vaccination.
Page last edited: 17 May 2011
- 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.