title: Impact of serum vitamin D level on risk of bladder cancer: a systemic review and meta-analysis.
abstract: Vitamin D has important biological functions including modulation of the immune system and anti-cancer effects. There was no conclusive finding of the impact of serum vitamin D level on bladder cancer risk. A systemic review and meta-analysis was performed to assess the impact of serum 25-hydroxyvitamin D level on bladder cancer risk. The pooled relative risk (RR) with 95% confidence interval (95%CI) was used to assess the impact of serum 25-hydroxyvitamin D level on bladder cancer risk. A total of 89,610 participants and 2238 bladder cancer cases were finally included into the meta-analysis. There was no obvious heterogeneity among those included studies (I(2) = 0%). Meta-analysis total included studies which showed that a high serum 25-hydroxyvitamin D level could obviously decrease risk of bladder cancer (RR = 0.75, 95%CI 0.65-0.87, P < 0.001). In addition, the pooled RRs were not significantly changed by excluding any single study. The findings from the meta-analysis suggest an obvious protective effect of vitamin D against bladder cancer. Individuals with higher serum 25-hydroxyvitamin D levels suffer from less risk of subsequent bladder cancer.
authors.affiliation: Department of Urology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, No. 32, Section 2, West 1st Ring Road, Chengdu, 610072, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liao
authors.forename: Jian-Lin
authors.initials: JL
authors.lastname: Huang
authors.forename: Ming-Xing
authors.initials: MX
authors.lastname: Qiu
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Ma
mesh_terms: D016022:Case-Control Studies; D015331:Cohort Studies; D019587:Dietary Supplements; D006801:Humans; D012307:Risk Factors; D001749:Urinary Bladder Neoplasms / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D