Calcium Intake and the Pancreatic Cancer Risk: A Systematic Review and Meta-Analysis of Observational Studies.

Calcium plays a major role in apoptosis, cell proliferation, and various cellular mechanisms. It is also essential for the function of the pancreas. However, the association between calcium intake and pancreatic cancer is not clear. This study aims to clarify the links between calcium intake and pancreatic cancer risk using a systematic review and meta-analysis of observational studies. PubMed, Web of Science, Scopus, and Google Scholar were searched for eligible articles published through 31 August 2023. Case-control and cohort studies reporting the association between dietary and/or supplemental calcium intake and risk of pancreatic cancer using relative risk (RR), hazard ratio (HR), or odds ratio (OR) with 95% confidence interval (CI) were included. Meta-analysis using a random effect model was used to estimate the significance of the association. Eight studies were included. An inverse association between total calcium intake (dietary and supplement) and pancreatic cancer risk (RR, 0.83; 95% CI, 0.72-0.97; I² = 0%) was observed. However, the association between dietary calcium intake alone and pancreatic cancer risk did not reach a statistically significant level (RR, 0.91; 95% CI, 0.78-1.06; I² = 48%). Higher total calcium intake may reduce the risk of pancreatic cancer but the difference between sources of calcium (dietary vs. supplementation) requires further investigation. Also, due to the heterogeneity between the articles, the results of this study should be interpreted with caution.

Trial registration: PROSPERO Identifier: CRD42022331647.