title: Associations between holotranscobalamin, vitamin B12, homocysteine and depressive symptoms in community-dwelling elders.
abstract: BACKGROUND
  Vitamin B12 and homocysteine have been shown to be associated with depression or depressive symptoms, but the relationship has not been universal. Both vitamin B12 and homocysteine may exert an effect via vascular mechanisms; it is possible that other mechanisms apply. Holotranscobalamin is a novel, more accurate measure of tissue vitamin B12.
  
  
  OBJECTIVE
  To examine associations between vitamin B12, serum folate, holotranscobalamin, homocysteine and depressive symptoms in a sample of healthy elderly.
  
  
  METHODS
  Cross-sectional, observational community based study.
  
  
  RESULTS
  Lower levels of holotranscobalamin and vitamin B12 were associated with higher levels of depressive symptoms when controlled for Mini-mental state examination scores and psychosocial and cardiovascular risk factors. Homocysteine was not associated with depressive symptoms when biological and psychosocial covariates were included.
  
  
  CONCLUSIONS
  It is possible that low levels of vitamin B12 or holotranscobalamin are associated with depressive symptoms via mechanisms other than vascular pathology.
authors.affiliation: School of Biochemistry and Immunology, Trinity College, Dublin, Ireland. davidjrobinson@iol.ie
authors.forename: D J
authors.initials: DJ
authors.lastname: Robinson
authors.forename: C
authors.initials: C
authors.lastname: O'Luanaigh
authors.forename: E
authors.initials: E
authors.lastname: Tehee
authors.forename: H
authors.initials: H
authors.lastname: O'Connell
authors.forename: F
authors.initials: F
authors.lastname: Hamilton
authors.forename: A V
authors.initials: AV
authors.lastname: Chin
authors.forename: R
authors.initials: R
authors.lastname: Coen
authors.forename: A M
authors.initials: AM
authors.lastname: Molloy
authors.forename: J
authors.initials: J
authors.lastname: Scott
authors.forename: C J
authors.initials: CJ
authors.lastname: Cunningham
authors.forename: B A
authors.initials: BA
authors.lastname: Lawlor
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003866:Depressive Disorder / Q000097:blood* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D009660:Northern Ireland / Q000453:epidemiology; D010549:Personal Satisfaction; D011446:Prospective Studies; D014155:Transcobalamins / Q000032:analysis*; D014505:Urban Population; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D015415:Biomarkers; D014155:Transcobalamins; D006710:Homocysteine; D014805:Vitamin B 12