title: Folic acid supplements and colorectal cancer risk: meta-analysis of randomized controlled trials.
abstract: Numerous studies have investigated the effects of folic acid supplementation on colorectal cancer risk, but conflicting results were reported. We herein performed a meta-analysis based on relevant studies to reach a more definitive conclusion. The PubMed and Embase databases were searched for quality randomized controlled trials (RCTs) published before October 2014. Eight articles met the inclusion criteria and were subsequently analyzed. The results suggested that folic acid treatment was not associated with colorectal cancer risk in the total population (relative risk [RR] = 1.00, 95% confidence interval [CI] = 0.82-1.22, P = 0.974). Moreover, no statistical effect was identified in further subgroup analyses stratified by ethnicity, gender, body mass index (BMI) and potential confounding factors. No significant heterogeneity or publication bias was observed. In conclusion, our meta-analysis demonstrated that folic acid supplementation had no effect on colorectal cancer risk. However, this finding must be validated by further large studies.
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Qin
authors.affiliation: 1] Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China [2] Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.
authors.forename: Mulong
authors.initials: M
authors.lastname: Du
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Haina
authors.initials: H
authors.lastname: Du
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Yongqian
authors.initials: Y
authors.lastname: Shu
authors.affiliation: 1] Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China [2] Department of Genetic Toxicology, the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.
authors.forename: Meilin
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Lingjun
authors.initials: L
authors.lastname: Zhu
mesh_terms: D016588:Anticarcinogenic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D015179:Colorectal Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D019587:Dietary Supplements; D005492:Folic Acid / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D012306:Risk
chemical_list: D016588:Anticarcinogenic Agents; D005492:Folic Acid