[Folate deficiency, cancer and congenital abnormalities. Is there a connection?]

The biochemical role of folate is in the interconversion of one-carbon units in intermediary metabolism; a process in which a methyl group is formed de novo. The methyl group is subsequently transferred to adenosylmethionine, which is an important methyl donor in the methylation of DNA. A negative correlation exists between the intake of folate in pregnancy and the occurrence of neural tube defects and certain malignant brain tumours in children. Numerous clinical studies have pointed to an association between folate status in adults and both the occurrence of cancer and the premalignant changes, cervical dysplasia, bronchial metaplasia, and colorectal adenomas. Folate deficiency may cause chromosomal damage, due to impaired DNA synthesis or repair. Moreover, decreased production of adenosylmethionine may influence the expression of developmental genes and of oncogenes and/or tumour suppressor genes through disturbed methylation of DNA.