A Meta-Analysis of Calcium Intake and Risk of Glioma

Background A meta-analysis was conducted to investigate the correlation between calcium intake and the risk of brain tumors (especially glioma). Methods The PubMed, Web of Science, and Embase databases were searched for relevant papers on the association between calcium intake and glioma as of August 22, 2021. The odds ratio (OR) with a 95% confidence interval (CI) was calculated using a random-effects model. Egger's test was conducted to assess publication bias. Results The meta-analysis includes four studies. The meta-analysis showed that calcium intake and the risk of brain tumors have a significant negative relationship (OR = 0.28; 95% CI: 0.11 to 0.72; P = 0.008). Dose-response analysis showed that for every 100 mg/day increase in calcium intake, the risk of glioma decreased by 7% (OR = 0.93; 95% CI: 0.88 to 0.98). In addition, compared with humans without calcium intake, when calcium intake is 455 mg/day, 800 mg/day and 1000 mg/day, the risk of glioma is 0.65 (95% CI 0.43, 0.97), 0.55 (95% CI 0.37, 0.82) and 0.37 (95% CI 0.15, 0.86). Conclusion There is a significant negative association between calcium intake and brain tumors (especially gliomas), but more high-quality studies are needed to verify these results.