The following list of researches suggests that Vitamin D can decrease death from influenza by a significant factor.
If your read the full articles, you may notice, that some researches make an effort to downplay the role of Vitamin D even though the results of their studies are very conclusive. Ask yourself, where is the money.
PMC3092571Influenza, solar radiation and vitamin D
“The data support the hypothesis that a high vitamin D level, as that found in the summer, acts in a protective manner with respect to influenza as well as pneumonia.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3092571/
Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren
https://academic.oup.com/ajcn/article/91/5/1255/4597253
- Influenza A occurred in 18 of 167 (10.8%) children in the vitamin D3 group compared with 31 of 167 (18.6%) children in the placebo group [relative risk (RR), 0.58; 95% CI: 0.34, 0.99; P = 0.04].
- Asthma attacks occurred in 2 children receiving vitamin D3 compared with 12 children receiving placebo
- Several plausible mechanisms might explain how vitamin D could have reduced the risk of influenza A.
Serum 25-hydroxyvitamin D3 and the risk of pneumonia in an ageing general population
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6121423/#B52-ijms-19-02419
Conclusions These data suggest an inverse effect of serum 25(OH)D3 concentration on the risk of incident pneumonia in the general ageing population.
RE: Epidemic Influenza and Vitamin D
https://www.aipro.info/wp/wp-content/uploads/2017/08/EPIDEMIC-INFLUENZA-AND-VITAMIN-D.pdf
After 3 years, a total of 34 patients reported cold and influenza symptoms, 8in the vitamin D3 group vs. 26 in the placebo group.Only one subject had a cold/influenza while on 2,000 IU of vitamin D.“Vitamin D supplementation, particularly at higher doses, may protect against the ‘typical’ winter cold and influenza.”
Aging Adults and Seasonal Influenza: Does the Vitamin D Status (H)Arm the Body?
https://www.hindawi.com/journals/jar/2012/806198/
- current influenza vaccines do not offer optimal protection in this population
- VitD insufficiency increases susceptibility to influenza infection
Vitamin D and Influenza—Prevention or Therapy?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6121423/
- The final conclusion is that its significance as an anti-influenza agent remains unresolved, but it does not mean that these considerations are senseless. It is most important to realize that the broad spectrum of vitamin D activity does not exclude such a role
- the high numbers of winter influenza and pneumonia deaths in Norway were related to low vitamin D levels in this season
- The positive role of vitamin D in respiratory infections and lung function was confirmed