Document Type: Systematic Review and Meta-analysis
Faculty of Public Health, Ilam University of Medical Sciences, Ilam, Iran.
Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran.
Department of Pathobiology, Ilam University of Medical Sciences, Ilam, Iran.
Psychosocial Injuries Research Center, Ilam University of Medical Sciences, Ilam, Iran.
Background: Controversial results have been reported concerning the influence of calcium intake on prostate cancer
risk. The aim of this study was to determine any association between total calcium (in the diet and in supplements) intake
and prostate cancer. Materials and Methods: The present systematic review and meta-analysis study was carried out
following a PRISMA guidelines. Two reviewers independently using MeSH keywords searched international databases
including PubMed, Science Direct, Cochrane, EMBASE, Web of Science, CINAHL, EBSCO and search engines such
as Google Scholar. The searches were performed without any time limit until May 2016. The results were pooled
using a random effects model and homogeneity was confirmed using the Q test and I2 index. Subgroup analyses was
performed according to continents and study designs. The data were analyzed using STATA software version 3.2, with
pfinal meta-analysis. The main age range of the participants was 50 to 70 years. The relative risks (RR) for total calcium
with total prostate cancer, localized prostate cancer, and advance prostate cancer were estimated to be 1.15 (95% CI:
1.04-3.46), 1.05 (95% CI: 0.96-1.14), and 1.15 (95% CI: 0.89-1.50), respectively. Only the relationship between total
calcium and total prostate cancer was significant (P<0.05). Conclusions: High calcium intake can be considered as a
risk factor for total prostate cancer. Therefore, calcium intake might be a target for prevention.