Vitamin D deficiency is associated with increased risk of bladder carcinoma in the present study. - GreenMedInfo Summary

BACKGROUND/AIMS: Vitamin D status in relation to bladder carcinoma risk was still inconsistent. This study was carried out to evaluate the relationship between vitamin D status and bladder carcinoma risk through a meta-analysis approach.

METHODS: Pubmed, Web of Science, CNKI, and Embase were searched systemically to find eligible studies from the earliest available date to April 16, 2015. The search terms"vitamin D","25-hydroxyvitamin D","bladder cancer"or"bladder carcinoma"were used to retrieve relevant studies. The exposure of interest was intake of vitamin D or serum vitamin D levels, and the outcome of interest was bladder carcinoma incidence or mortality. The pooled risk ratio (RR) values and their 95%CIs were calculated through meta-analysis.

RESULTS: Seven studies with a total of 62,141 participants met the inclusion criteria and were finally included into the meta-analysis. There was no heterogeneity among those included studies (I2 = 0%, P = 0.53). The pooled RR of bladder carcinoma for the lowest category versus the highest category of vitamin D was 1.34 (95% CI 1.17-1.53, P<0.0001). Sensitivity analysis by omitting one study by turns showed all the pooled RRs were statistically significant. Meta-analysis of 5 studies reporting outcomes of serum vitamin D levels also showed that the low serum vitamin D level was associated with increased risk of bladder carcinoma (RR = 1.32, 95%CI 1.15-1.52, P = 0.0001). No obvious risk of publication bias was observed.

CONCLUSION: Vitamin D deficiency is associated with increased risk of bladder carcinoma in present study.