Review Circulating folate, vitamin B12, homocysteine, vitamin B12 transport proteins, and risk of prostate cancer: a case-control study, systematic review, and meta-analysis.
Collin SM, Metcalfe C, Refsum H, Lewis SJ, Zuccolo L, Smith GD, Chen L, Harris R, Davis M, Marsden G, et al. Cancer Epidemiol Biomarkers Prev. 2010 Jun; 19(6):1632-42. Epub 2010 May 25.