title: Homocysteine, folate, vitamin B-12, and 10-y incidence of age-related macular degeneration.
abstract: BACKGROUND
  Epidemiologic evidence of a relation between serum total homocysteine (tHcy), vitamin B-12, and folate and age-related macular degeneration (AMD) is inconsistent and unresolved.
  
  
  OBJECTIVE
  In this cohort study, we aimed to investigate associations between intakes and serum concentrations of folate and vitamin B-12 or serum tHcy and 10-y AMD incidence.
  
  
  METHODS
  Serum folate, vitamin B-12, and tHcy were determined from blood samples drawn in 1997-1999 from cohort members aged ≥55 y. AMD was assessed in 1760 survivors from retinal photographs taken in 2002-2004 and 2007-2009. Total intakes of folate and vitamin B-12 were assessed by using a food-frequency questionnaire.
  
  
  RESULTS
  After adjustment for age, sex, current smoking, white blood cell count, and fish consumption, each 1-SD increase in serum tHcy was associated with increased risk of incident early and any AMD [ORs (95% CIs): 1.33 (1.09, 1.63) and 1.33 (1.11, 1.60), respectively]. Participants with a serum vitamin B-12 deficiency (<185 pmol/L) had higher risk of incident early and late AMD [ORs (95% CIs): 1.58 (1.06, 2.36) and 2.56 (1.38, 4.73), respectively]. Folate deficiency (<11 nmol/L) was associated with 75% and 89% increased risk of incident early and any AMD, respectively, 10 y later. Participants who reported supplementary vitamin B-12 intake had 47% reduced risk of incident any AMD (OR: 0.53; 95% CI: 0.33, 0.85).
  
  
  CONCLUSIONS
  Elevated serum tHcy and folate and vitamin B-12 deficiencies predicted increased risk of incident AMD, which suggests a potential role for vitamin B-12 and folate in reducing AMD risk.
authors: Centre for Vision Research, Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia.
authors: Bamini
authors: B
authors: Gopinath
authors: Victoria M
authors: VM
authors: Flood
authors: Elena
authors: E
authors: Rochtchina
authors: Jie Jin
authors: JJ
authors: Wang
authors: Paul
authors: P
authors: Mitchell
mesh_terms: D000368:Aged; D000818:Animals; D005260:Female; D005399:Fishes; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood*; D005494:Folic Acid Deficiency / Q000150:complications / Q000453:epidemiology; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D015994:Incidence; D007958:Leukocyte Count; D008268:Macular Degeneration / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000150:complications / Q000453:epidemiology
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12