Supplement use among cancer patients is high, and folic acid intake in particular may adversely affect the progression of colorectal cancer. Few studies have evaluated the use of folic acid-containing supplements (FAS) and its predictors in colorectal cancer patients.
National Center for Tumor Diseases Heidelberg, Division of Preventive Oncology, German Cancer Research Center, Im Neuenheimer Feld 581, Heidelberg, Germany.