With growing concern over the relationship between folic acid supplementation and cancer risk a meta-analysis was conducted to better elucidate the relationship. The analysis reported no increased risk of total cancer incidence, colorectal cancer, prostate cancer, lung cancer, breast cancer, or hematological malignancy, and a significant reduced risk of melanoma.

As reported:

  • Total cancer incidence (13 trials, n = 49,406, RR = 1.05; 95% CI: 0.99-1.11, p = 0.13)
  • Colorectal cancer (seven trials, n = 33,824, RR = 1.01; 95% CI: 0.82-1.23, p = 0.95)
  • Other gastrointestinal cancer (two trials, n = 20,228, RR = 1.00; 95% CI: 0.75-1.33, p = 0.99)
  • Prostate cancer (five trials, n = 27,065, RR = 1.17; 95% CI: 0.84-1.62, p = 0.35)
  • Other genitourinary cancer (two trials, n = 20,228, RR = 0.97; 95% CI: 0.75-1.27, p = 0.84)
  • Lung cancer (five trials, n = 31,864, RR = 1.00; 95% CI: 0.84-1.21, p = 0.97)
  • Breast cancer (four trials, n = 19,800, RR = 0.82; 95% CI: 0.63-1.07, p = 0.15)
  • Hematological malignancy (three trials, n = 25,670, RR = 0.87; 95% CI: 0.64-1.17, p = 0.35)
  • Total cancer mortality (six trials, n = 31,930, RR = 1.02; 95% CI: 0.90-1.15, p = 0.81)
  • Melanoma (three trials, n = 19,128, RR = 0.47; 95% CI: 0.23-0.94, p = 0.03).

Int J Cancer. 2013 Sep 1;133(5):1033-41. PMID: 23338728