1.
Vitamin D can safely reduce asthma exacerbations among corticosteroid-using children and adults with asthma: a systematic review and meta-analysis of randomized controlled trials.
Chen, Z, Peng, C, Mei, J, Zhu, L, Kong, H
Nutrition research (New York, N.Y.). 2021;:49-61
Abstract
Previous studies have failed to draw a consistent conclusion over the effect of vitamin D administration on asthma. We hypothesized that vitamin D supplementation could improve the clinical efficacy of corticosteroids in patients with asthma as measured by exacerbations, Asthma Control Test (ACT) score, and lung function in order to maintain asthma control. We searched Web of Science, PubMed, the Cochrane Library, and ScienceDirect up through January 20, 2021 for randomized controlled trials analyzing the effect of vitamin D supplementation on asthma exacerbation. Studies were limited to patients with moderate to severe asthma who were treated with corticosteroids. We identified 12 studies involving 1,543 participants in this meta-analysis. Vitamin D supplementation significantly reduced the risk of asthma exacerbation (pooled risk ratio (RR) 0.70, 95% confidence interval (CI), 0.59, 0.83; P < .05). The pooled RR of the ACT score was 0.04 (95% CI, -0.19, 0.27; P > .05). The pooled standardized mean difference in vitamin D levels was 1.07 (95% CI, 0.77, 1.38; P < .05), and in the percentage of forced expiratory volume in one second was -0.02 (95% CI, -0.13, 0.09; P > .05). The pooled RR of adverse events was 1.06 (95% CI, 0.89, 1.25; P > .05). We performed subgroup analysis and meta-regression of serum vitamin D levels but found no source of heterogeneity. Vitamin D supplementation safely reduced the rate of asthma exacerbation but did not improve ACT score or lung function among patients with asthma treated with corticosteroids.
2.
Ascorbic Acid Supplements and Kidney Stones Incidence Among Men and Women: A systematic review and meta-analysis.
Jiang, K, Tang, K, Liu, H, Xu, H, Ye, Z, Chen, Z
Urology journal. 2019;(2):115-120
Abstract
PURPOSE The relationship of ascorbic acid (AA) supplements and risk of kidney stones among men and women is controversial. This systematic evaluation was performed to obtain comprehensive evidence about the relationship of AA supplements and risk of kidney stones among men and women. MATERIAL AND METHODS A systematic search of Pubmed, the Cochrane Library, Web of Science, Embase was performed to identify studies that exhibited the relationship of AA supplements and risk of kidney stones among men and women were published up to Mar 2017. Outcomes of interest included kidney stones incidence and risk factors. RESULTS Four studies estimating the association between AA supplements and risk of kidney stones were included for meta-analysis. The kidney stones incidence was significantly higher in men than women with AA supplements (OR= 1.62; 95% CI: 1.09 to 2.42; P=0.02). AA supplements (250-499mg/d, 1000-1499mg/d) was remarkably correlated with the risk of renal stones among men (OR= 1.14, 95% CI: 1.00 to 1.28, P=0.04; OR= 1.12, 95% CI: 1.11 to 1.13, P<0.00001; respectively). However, AA supplements (500-999 mg/d, >1500 mg/d) did not correlate with the risk of renal stones among men (OR= 1.20, 95% CI: 0.99 to 1.46, P=0.06; OR= 1.28, 95% CI: 1.00 to 1.63, P= 0.05; respectively). In addition, AA supplements (250-499mg/d, 500-999mg/d, 1000-1499mg/d, >1500mg/d) did not remarkably correlate with the risk of renal stones among women (OR= 1.00, 95% CI: 0.82 to 1.22, P=0.98; OR= 1.08, 95% CI: 0.99 to 1.18, P=0.09; OR= 0.99, 95% CI: 0.90 to 1.08, P=0.77; OR= 0.99, 95% CI: 0.99 to 1.09, P=0.88; respectively). CONCLUSIONS AA supplements was remarkably correlated with higher risk for kidney stones incidence in men, but not in women. Further multicenter, prospective and long-term follow-up RCTs are required to verify these findings.