title: Vitamin B12 and folate deficiency: should we use a different cutoff value for hematologic disorders?
abstract: BACKGROUND
  Anemia and macrocytosis are well-defined expected hematologic findings of vitamin B12 and folate deficiency; however, some previous studies did not show a significant association of subnormal B12 with anemia and macrocytosis.
  
  
  METHODS
  We retrospectively analyzed 17 713 laboratory patient records to evaluate vitamin B12 and folate levels in relation to anemia and macrocytosis.
  
  
  RESULTS
  In an age- and sex-adjusted logistic regression model, low B12 status but not marginal B12 status was significantly associated with anemia [ORs respectively, 1.291 (95% CI, 1.182-1.410), 1.022 (95% CI, 0.943-1.108)] and macrocytosis [ORs, respectively, 3.853 (95% CI, 3.121-4.756), 1.031 (95% CI, 0.770-1.381)]. Also low folate status but not marginal folate status was significantly associated with anemia [adjusted ORs, respectively, 1.819 (95% CI, 1.372-2.411), 1.101 (95% CI, 0.931-1.301)] and macrocytosis [adjusted ORs, respectively, 2.945 (95% CI, 1.747-4.965), 1.228 (95% CI, 0.795-1.898)].
  
  
  CONCLUSIONS
  Our results show that increased anemia and macrocytosis are observed at values below commonly used B12 lower-reference thresholds. Determining a hematologic cutoff value may help physicians in clinical practice.
authors.affiliation: Department of Clinical Biochemistry, Tepecik Training and Research Hospital, Izmir, Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Toprak
authors.forename: H Z
authors.initials: HZ
authors.lastname: Yalcın
authors.forename: A
authors.initials: A
authors.lastname: Colak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000748:Anemia, Macrocytic / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005494:Folic Acid Deficiency / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012189:Retrospective Studies; D014805:Vitamin B 12 / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology
chemical_list: D005492:Folic Acid; D014805:Vitamin B 12
keywords: Anemia; B12; cutoff value; folate; macrocytosis