Folic acid supplements and colorectal cancer risk: meta-analysis of randomized controlled trials

Sci Rep. 2015 Jul 1;5:12044. doi: 10.1038/srep12044.


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.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anticarcinogenic Agents / administration & dosage*
  • Anticarcinogenic Agents / adverse effects
  • Colorectal Neoplasms / chemically induced
  • Colorectal Neoplasms / prevention & control*
  • Dietary Supplements*
  • Folic Acid / administration & dosage*
  • Folic Acid / adverse effects
  • Humans
  • Randomized Controlled Trials as Topic
  • Risk


  • Anticarcinogenic Agents
  • Folic Acid