title: No effect of vitamin B-12 treatment on cognitive function and depression: a randomized placebo controlled study.
abstract: BACKGROUND
  Associations between vitamin B-12 deficiency and impaired cognitive function and depression have been reported.
  
  
  METHODS
  A randomized placebo controlled study including 140 individuals with an increased plasma methylmalonic acid (0.40-2.00 micromol/l) not previously treated with vitamin B-12. Cognitive function was assessed by the Cambridge Cognitive Examination (CAMCOG), Mini-Mental State Examination (MMSE), and a 12-words learning test. Symptoms of depression were evaluated by the Major Depression Inventory. The main outcome measure was change in cognitive function and depression score from baseline to follow-up 3 months later.
  
  
  RESULTS
  At baseline 78 (56%) individuals had cognitive impairment judged from the CAMCOG score and 40 (29%) according to the MMSE; 18 (13%) individuals had symptoms of depression. No improvement was found in cognitive function comparing the treatment and placebo group (total CAMCOG score: P = 0.43), nor among individuals with only slightly impaired cognitive function (n = 44, total CAMCOG score: P = 0.42). The treatment group did not improve in depression score as compared to the placebo group (P = 0.18).
  
  
  CONCLUSIONS
  The duration of impaired cognitive function was unknown.
  
  
  CONCLUSIONS
  A high proportion of individuals with an increased plasma methylmalonic acid had impaired cognitive function, and a rather high prevalence of depression was observed. However, vitamin B-12 treatment did not improve cognitive function or symptoms of depression within the 3-months study period.
authors.affiliation: Department of Haematology, AAS, Aarhus University Hospital, Aarhus, Denmark. am.hvas@dadlnet.dk
authors.forename: Anne-Mette
authors.initials: AM
authors.lastname: Hvas
authors.forename: Svend
authors.initials: S
authors.lastname: Juul
authors.forename: Lise
authors.initials: L
authors.lastname: Lauritzen
authors.forename: Ebba
authors.initials: E
authors.lastname: Nexø
authors.forename: Jørgen
authors.initials: J
authors.lastname: Ellegaard
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology*; D003866:Depressive Disorder / Q000150:complications* / Q000188:drug therapy* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D010919:Placebos; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014805:Vitamin B 12 / Q000494:pharmacology* / Q000627:therapeutic use*
chemical_list: D010919:Placebos; D014805:Vitamin B 12