Association Between Serum Vitamin D Level And Adult Bronchial Asthma:a Meta-Analysis

Objective:To investigate the relationship between serum vitamin D level and bronchial asthma in adults.Methods:We searched The CoChrane Library,PubMed,EMbase,Web of science,OVID,Springerlink,Wiley online library,ScienceDirect,EBSCOhost,CNKI,VIP,WanFang data databases from inception to May 1st 2017 to collect studies about the association between vitamin D and adult asthma.Two reviewers independently screened literature according to inclusion and exclusion standard,extracted data and assessed the quality of included studies.Then,meta-analysis was performed using RevMan5.3 software.Results:Nine case-control studies involving 827 asthma patients and 287 controls were finally included.The meta-analysis showed that 25(OH)D in adult asthma group was lower than that in control group[MD=-15.90,95%CI(-18.55,-13.25),P<0.01].Adult asthma presented more vitamin D deficiency than the controls[RR=2.03,95%CI(1.57,2.63),I~2=0%,P=0.79].In asthma patients,FEV1%in vitamin D deficiencies was lower than the normal[MD=-9.78,95%CI(-12.21,-7.36),P<0.01].Conclusion:Vitamin D level is associated with asthma in adults.Vitamin D deficiency is common in patients with asthma and associated with lung function.The lack of vitamin D may be one of the potential risk factors for asthma.