The relationship between folic acid and colorectal cancer
CRC is one of the most threatening tumors, comprising 10.2% of all diagnosed tumors and 9.2% of cancer-related mortality worldwide . In 2018, it was ranked the third malignancy in incidence, and the second malignancy in mortality related to cancer . The CRC rates are expected to increase  despite the screening programs . Vit-B9 (folic acid; FA) is a water-soluble vitamin that plays a significant role in de novo synthesis of purines and thymidine as well as its essential role in preventing several disorders such as megaloblastic anemia, atherosclerosis, neural tube defects and cancer . Herein, we aim to clarify the relationship between folic acid and CRC.