Purpose
This meta-analysis aimed to generate a comprehensive overview of relationship between plasma 25-hydroxyvitamin D [25(OH)D] and pancreatic cancer (PC) incidence and mortality.
Methods
PubMed, Embase and Wed of Science databases were searched through February 15, 2022. A random-effects model was used to estimate total relative risks (RRs) and 95% confidence intervals (CIs). Subgroup, meta-regression, sensitivity and publication bias analyses were employed in this systematic review and meta-analysis.
Results
After exclusion of ineligible studies, a total of 16 studies that involved 538,673 participants were included in our meta-analysis, of which 10 reported incidence and 6 reported mortality. For the highest versus the lowest plasma 25(OH)D levels, the summary RR of PC incidence was 0.99 (95% CI 0.70–1.29), and the summary RR of PC mortality was 0.78 (95% CI 0.57–0.98). Subgroup analyses showed an inverse association between plasma 25(OH)D and PC incidence in America (RR = 0.70; 95% CI 0.45–0.96) but not in Europe (RR = 1.36; 95% CI 0.86–1.86). Furthermore, plasma 25(OH)D was associated with PC incidence when the duration of follow-up was longer than 10 years (RR = 0.70; 95% CI 0.43–0.97) and when adjusted for race (RR = 0.64; 95% CI 0.35–0.93). The association between plasma 25(OH)D and PC mortality was overall consistent in stratified analyses.
Conclusion
High plasma 25(OH)D may be associated with the lower PC mortality, but not significantly associated with PC incidence. Our findings may have implications for antitumor therapy in PC patients, as well as caution in increasing vitamin D intake in the general population.