title: Association of dietary intake of folate, vitamin B6 and B12 and MTHFR genotype with breast cancer risk.
abstract: OBJECTIVE
  We aimed to investigate the associations of dietary intake of folate, vitamin B6 and B12 and MTHFR genotype with breast cancer in a Chinese population.
  
  
  METHODS
  A matched case-control study was conducted, and 435 patients with newly diagnosed and histologically confirmed breast cancer and 435 controls were collected. The folate intake, vitamin B6 and vitamin B12 were calculated, and MTHFR C665T, C677T and A1298C were analyzed by PCR-RFLP.
  
  
  RESULTS
  We found vitamin B12 was likely to reduce the risk of breast cancer, and MTHFR 665TT was associated with increased risk of breast cancer. Folate intake, vitamin B12 intake and variants of MTHFR C677T and MTHFR A1298C demonstrated no association with risk of breast cancer. However, we found patients with low intake of vitamin B6 and MTHFR 665TT genotype had a higher risk of breast cancer (OR=1.87, 95% CI=1.29-2.77), the association being less pronounced among subjects with a moderate intake of vitamin B6 and MTHFR 665TT genotype (OR=1.58, 95% CI=1.03-2.49, P=0.03).
  
  
  CONCLUSIONS
  Our study indicated that the MTHFR C665T polymorphism and vitamin B6 are associated with risk of breast cancer, which indicated roles for nutrients in developing breast cancer.
authors.affiliation: The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China E-mail : liuyin1993@126.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Long-Shu
authors.initials: LS
authors.lastname: Zhou
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Xu
authors.forename: Liang-Qing
authors.initials: LQ
authors.lastname: Deng
authors.forename: Qian-Kun
authors.initials: QK
authors.lastname: Xiao
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics* / Q000706:statistics & numerical data; D001943:Breast Neoplasms / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004032:Diet / Q000706:statistics & numerical data*; D004435:Eating; D005260:Female; D005492:Folic Acid; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D065840:Protective Factors; D014805:Vitamin B 12; D025101:Vitamin B 6
chemical_list: D025101:Vitamin B 6; D005492:Folic Acid; C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12