Effectiveness And Safety Of Vitamin D In Treatment Of Patients With Asthma During Remission Stage:a Meta-analysis

Objective To investigate whether vitamin D supplementation can reduce the number of acute exacerbations in asthma patients(including acute exacerbation of asthma requiring systemic corticosteroids therapy and need for emergency or hospital visits or both),and improve lung function(FEV1% Predicted values),serum 25-hydroxyvitamin D levels and other clinical indicators,systematic evaluation of vitamin D in the treatment of asthma disease value and safety,provide evidence-based reference for clinical treatment.Methods We searched Pubmed,Medline,ISI Web of Science,Embase,Cachrane Library,CNKI,CBM,VIP and Wan fang database to identify relevant studies including the words:asthma /??,vitamin D /??? D,lung function,search timeframe is from library building to October 8,2017.All of randomized controlled trials(RCTs)of vitamin D supplementation in patients with asthma were searched,and research literatures included in the RCTs were also traced.Two researchers independently conducted the strict quality evaluation and data extraction for the included studies and conducted the heterogene-ities test and sensitivity analysis.Meta analysis was performed by using the Cochrane review software Review Manager 5.3.5(Rev Man 5.3.5),shown in the forest map.Results Twelve literatures including 649 cases of experimental group and control group 646 cases were finally enrolled in this study.Meta analysis showed that:1)In the number of acute exacerbations of asthma,the pooled OR of Vit D supplement group and placebo supplement group was 0.53(95%CI:0.28-0.99,P=0.05);2)In acute exacerbation of asthma requiring systemic corticosteroids therapy,the combined RR of Vit D supplement group and the placebo supplement group was 0.64(95%CI: 0.46-0.90,P=0.01);3)In patients in the Vit D supplement group and the placebo supplement group who required acute exacerbation of the emergency department or hospitalization or both,the combined OR was 0.39(95%CI:0.19-0.78,P=0.008);4)Supplementation of Vit D and placebo in the incidence of adverse events,the combined RR was 1.02,(95% CI:0.69-1.15,P=0.91);5)In the first second forced ventilatory volume(FEV1)percentage predicted(FEV1% predicted)for the Vit D supplemented versus placebo supplemented group,the combined SMD was 0.24(95% CI 0.06-0.42,P = 0.010);6)Compared with baseline,serum 25-hydroxyvitamin D changes at 2-month and 12-month follow-up in the Vit D supplement group and the placebo supplement group,the combined were 0.54(95%CI:0.28-0.79),1.03(95%CI:0.78-1.28),overall effect(Z=5.01,P<0.00001);7)In a fatal asthma exacerbation,the combined RD was 0.00(95%CI:-0.01-0.01,P=1.00).Conclusion 1)Vit D intervention significantly reduced acute exacerbation of asthma,including acute exacerbation of asthma requiring systemic corticosteroid treatment and acute exacerbation of asthma requiring emergency department or hospitalization or both,with statistically significant differences;2)In the results of FEV1% of lung function,the difference was statistically significant,suggesting that Vit D supplementation could significantly improve pulmonary function;3)In the results of serum 25-hydroxyvitamin D,the difference was statistically significant,suggesting that Vit D supplementation can significantly increase serum 25-hydroxyvitamin D;4)The impact of Vit D intervention on the occurrence of adverse events,the results were not statistically significant;5)This systematic review will statistically analyze randomized controlled trials of the effect of Vit D on acute asthma attacks,pulmonary function,serum 25-hydroxyvitamin D,and provide evidence-based medical evidence for vitamin D supplementation as a routine treatment for asthma.But more rigorous,large-scale clinical randomized controlled trials are still needed to further validate the clinical efficacy and safety of vitamin D supplements in asthmatic patients.