Homocysteine, folate, vitamin B-12, and 10-y incidence of age-related macular degeneration

Am J Clin Nutr. 2013 Jul;98(1):129-35. doi: 10.3945/ajcn.112.057091. Epub 2013 May 1.

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.

Design: 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).

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Animals
  • Female
  • Fishes
  • Folic Acid / administration & dosage
  • Folic Acid / blood*
  • Folic Acid Deficiency / complications
  • Folic Acid Deficiency / epidemiology
  • Homocysteine / blood*
  • Humans
  • Incidence
  • Leukocyte Count
  • Macular Degeneration / epidemiology*
  • Macular Degeneration / etiology
  • Male
  • Middle Aged
  • Prospective Studies
  • Risk Factors
  • Surveys and Questionnaires
  • Vitamin B 12 / administration & dosage
  • Vitamin B 12 / blood*
  • Vitamin B 12 Deficiency / complications
  • Vitamin B 12 Deficiency / epidemiology

Substances

  • Homocysteine
  • Folic Acid
  • Vitamin B 12