SynthesisCancer medicine2026
Vitamin D and Bladder Cancer Risk: An Umbrella Review and Second Order Meta-Analysis.
Synthesis in Cancer medicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
1 citing paper in PubMed.
- The Insulin-Urothelial Axis: Evaluating Insulin Resistance as a Convergent Driver of Bladder Cancer Across Diverse Risk Factor Profiles.International journal of molecular sciences · 2026Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
11 authors.
Funding
Abstract
introductionBladder cancer is a common malignancy with a high recurrence rate, posing a significant public health burden. Beyond its role in bone health, vitamin D has been suggested to influence cancer risk, including bladder cancer.
aimTo evaluate the association between serum vitamin D levels, dietary intake, and supplementation with bladder cancer risk.
methodsThis umbrella review included systematic reviews and meta-analyses from multiple databases, focusing on serum levels or intake of vitamin D and bladder cancer risk. Study quality was assessed using the JBI Critical Appraisal Tool. The Corrected Covered Area showed a 15.5% overlap. Considerable heterogeneity in study design, populations, and vitamin D assessment was noted. Two second-order meta-analyses were conducted for quantitative synthesis.
resultsEight studies met the inclusion criteria. Adequate serum vitamin D was generally defined as levels ≥ 30 nmol/L. Low serum vitamin D was significantly associated with increased bladder cancer risk (RR = 1.32; 95% CI: [1.27, 1.38]). Higher serum levels were linked to a non-significant risk reduction (RR = 0.86; 95% CI: [0.63, 1.16]). Evidence on dietary intake was inconsistent, with some analyses suggesting a modest protective effect, particularly when combined with specific dietary patterns.
conclusionsLow serum vitamin D is consistently associated with increased bladder cancer risk, while maintaining levels above 30 nmol/L may provide some protection. Evidence on dietary intake and supplementation remains inconclusive. Future studies should adopt standardized methods for vitamin D measurement, explore the role of free versus total vitamin D, and clarify population-specific differences to better define vitamin D's role in bladder cancer prevention.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.