title: Vitamin B12 and health.
abstract: OBJECTIVE
  To review recent evidence that suggests vitamin B12 is associated with risk reduction for some chronic diseases and birth defects.
  
  
  METHODS
  A MEDLINE search from 1999 to 2007 was performed using the key word vitamin B12. The most relevant articles (129) dealt with cardiovascular disease, cancer, mental health, and birth outcomes;most studies presented level II evidence.
  
  
  RESULTS
  Vitamin B12 might confer health benefits; however, such benefits are difficult to ascertain because of the complementary functions of vitamin B12 and folic acid. Vitamin B12 might lower high homocysteine levels below a threshold level achieved by folic acid alone. Furthermore, the interactions between the nutritional environment and genotype might have an important influence on vitamin B12, chronic disease risk, and risk of neural tube defects.
  
  
  CONCLUSIONS
  Vitamin B12 might help protect against chronic disease and neural tube defects, but more research, particularly in the area of nutritional genomics, is needed to determine how vitamin B12 might augment the benefits of folic acid. Some consideration should be given to the potential value of fortifying foods with vitamin B12 in addition to the current mandatory folic acid fortification of grains.
authors.affiliation: FEAST Enterprises, 947 Oshawa Blvd N, Oshawa, ON L1G 5V6. ryanharshman@rogers.com
authors.forename: Milly
authors.initials: M
authors.lastname: Ryan-Harshman
authors.forename: Walid
authors.initials: W
authors.lastname: Aldoori
mesh_terms: D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control; D000013:Congenital Abnormalities / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D001523:Mental Disorders / Q000209:etiology / Q000517:prevention & control; D009369:Neoplasms / Q000209:etiology / Q000517:prevention & control; D014805:Vitamin B 12 / Q000502:physiology* / Q000627:therapeutic use; D014806:Vitamin B 12 Deficiency / Q000150:complications* / Q000517:prevention & control / Q000523:psychology; D014803:Vitamin B Complex / Q000627:therapeutic use
chemical_list: D014803:Vitamin B Complex; D014805:Vitamin B 12