Introduction
Vitamin D (vitD) may influence bladder cancer (BC) both directly or indirectly via the uptake of calcium and phosphorus,. The aim of this study was to investigate the relation between vitD intake and BC risk.

Methods
Individual dietary data were pooled from two cohort studies. Pooled multivariate hazard ratios(HR), with corresponding 95% confidence intervals(95%CI) were obtained using Cox-regression models. Analyses were adjusted for gender, age and smoking status (Model 1), and additionally for fruit, vegetables and meat intake (Model 2). Dose–response relationships were examined using a nonparametric test for trend.

Results
In total, 1,994 cases and 518,002 non-cases were included. The present study showed an increased BC risk for high dietary vitD intake overall, among women and for non-muscle invasive BC (HR_highVitD(95%CI):1.26(1.11-1.44), 1.64(1.29-2.09), 1.21(1.05-1.40), respectively). Similar increased BC risks were observed for high intake of phosphorus overall and among men (HR_highP(95%CI): 1.18(1.04-1.33), 1.16(1.01-1.34), respectively). 
Combining the intake of vitD and calcium decreased BC risks were observed (HR_{modVitD,modCa}:1.22, 95%CI:1.03-1.45, HR_{highVitD,highCa}:1.20, 95%CI:1.02-1.42). VitD intake combined with phosphorus showed increased BC risks (HR_{highVitD,lowP}:1.31, 95%CI:1.09-1.59, HR_{highVitD,modP}:1.17, 95%CI:1.01-1.36, HR_{highVitD,highP}:1.16, 95%CI:1.03-1.31). 
Combining all nutrients a similar pattern was observed in that a decreased BC risk was observed with low intake of vitD, moderate phosphorus, and high intake of calcium (HR_{lowVitD,highCa,modP}:0.41, 95%CI:0.20-0.83), and an increased BC risk if calcium intake was either low or all nutrients were highly consumed (HR_{lowVitD,lowCa,highP}:1.64, 95%CI:1.07-2.53, HR_{modVitD,modCa,modP}:1.29, 95%CI:1.03-1.60, HR_{modVitD,modCa,highP}:1.57, 95%CI:1.18-2.10, HR_{highVitD,lowCa,lowP}:1.35, 95%CI:1.05-1.75, HR_{highVitD,modCa,highP}:1.37, 95%CI:1.07-1.74, HR_{highVitD,highCa,modP}:1.45, 95%CI:1.12-1.88, : HR_{highVitD,highCa,highP}:1.28, 95%CI:1.06-1.54). No significant dose-response analyses were observed.

Conclusion
This study showed an increased BC risk for high dietary vitD and phosphorus intake, contradicting results for calcium intake and highlights the importance of examining the effect of a nutrient in combination with complementary nutrients. Future research should focus on nutrients in a wider context and nutritional patterns.