title: Infrequency of low red blood cell (RBC) folate levels despite no folate fortification program: a study based on results from routine requests for RBC folate.
abstract: BACKGROUND
  We investigated the prevalence of a low level of red blood cell (RBC) folate in individuals suspected to be deficient and further evaluated the clinical consequence of identifying an individual with a low folate level in a population where no fortification with folate has been introduced.
  
  
  METHODS
  We conducted a retrospective review of all RBC folate analyses requested in one of the university hospitals in Denmark and identified patients with abnormally low (<350 nmol/L) and high (>1700nmol/L) folate levels. For requests from the hospital, we evaluated the clinicians' response to a decreased level of folate.
  
  
  RESULTS
  A total of 12,932 RBC folates requested from the hospital (26%) or from general practitioners (GPs) (74%) were investigated. RBC folate levels were low in a comparable fraction of those requested from the hospital (1.7%) and from the GPs (1.3%). A high level of RBC folate was observed more often than a low RBC folate and occurred considerably more frequently (p<0.0001) in patients referred from the hospital (4.9%) than amongst those referred from GPs (1.2%). The clinicians' response rate to a low folate was around 60% and occurred more often for patients with a low level of cobalamins than in other patients.
  
  
  CONCLUSIONS
  Low RBC folate values are rare in Danish patients despite no folate fortification program. Further, the clinical reaction to a low folate value is unexpectedly low.
authors.affiliation: Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark. vakbor@yahoo.com
authors.forename: Mustafa Vakur
authors.initials: MV
authors.lastname: Bor
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Wulff
authors.forename: Ebba
authors.initials: E
authors.lastname: Nexo
authors.forename: Henrik
authors.initials: H
authors.lastname: Krarup
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005494:Folic Acid Deficiency / Q000453:epidemiology*; D005527:Food, Fortified / Q000706:statistics & numerical data*; D006306:Health Surveys; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D010821:Physicians, Family; D012017:Referral and Consultation; D012189:Retrospective Studies
chemical_list: D005492:Folic Acid