One Carbon Metabolites and Prostate Cancer Risk

This study investigated components of one−carbon metabolism in relation to prostate cancer risk in a large prospective epidemiological study. Circulating plasma concentrations of betaine, cysteine, methionine, and vitamin B6 were not associated with prostate cancer risk, whereas elevated concentrations of choline and vitamin B2 may be associated with an increased risk.

Johansson et al (2009). "One-Carbon Metabolism and Prostate Cancer Risk: Prospective Investigation of Seven Circulating B Vitamins and Metabolites." Cancer Epidemiol Biomarkers Prev 18(5): 1538-1543.