The role of circulating 25 hydroxyvitamin D in asthma: a systematic review
Volume 70, Issue 4, pages 339–354, April 2015, DOI: 10.1111/all.12583
R. Cassim1, M. A. Russell1, C. J. Lodge1,2, A. J. Lowe1,2, J. J. Koplin1,2 andS. C. Dharmage1,2,*
Asthma is a major public health issue. The co-occurrence of the high prevalence of asthma and vitamin D deficiency documented globally in recent decades has prompted several investigations into a possible association between the two conditions. The objective of this paper was to synthesize the evidence from studies that have measured the association between serum vitamin D and asthma incidence, prevalence, severity and exacerbations. A systematic search of the literature was performed in PubMed, and the available evidence was summarized both qualitatively and by meta-analysis. Only English language, observational studies measuring serum levels of 25(OH)D as the exposure were included, as this is the most robust measure of vitamin D levels. The search identified 23 manuscripts: two case–control, 12 cohort and nine cross-sectional studies. Collectively, the evidence suggests that higher serum levels of 25(OH)D are associated with
- a reduced risk of asthma exacerbations, but there was
- little evidence to suggest an association with asthma incidence, prevalence or severity.
A significant amount of heterogeneity between study methodology and results restricted the scope for meta-analysis. These results suggest that vitamin D supplementation may be effective for the prevention of asthma exacerbations, but the findings need to be confirmed by clinical trials.
Download the PDF from Vitamin D Life
PDF contains tables which overview each of the 23 studies
See also Vitamin D Life
- Asthma reduced 60 percent with vitamin D supplementation – meta-analysis 2014, 2015
- Proof that Vitamin D Works
Asthma has been proven to be treated by Vitamin D in at least 4 random controlled trials - Asthma is treated by Vitamin D – now they are trying to understand why – Feb 2015
- Acute respiratory distress – 100 percent of patients were vitamin D deficient– April 2015
- Allergies and asthma – overwhelming experimental evidence that vitamin D helps – more studies needed – Dec 2014