title: Vitamin B12 deficiency in Australian residential aged care facilities.
abstract: OBJECTIVE
  To determine the prevalence of undiagnosed vitamin B12 deficiency among residential aged care facility residents in southern Tasmania, Australia, and to identify associated risk factors.
  
  
  METHODS
  Cross-sectional study of residents from five southern Tasmanian residential aged care facilities.
  
  
  METHODS
  Two hundred and fifty-nine residents without a prior diagnosis of vitamin B12 deficiency or recorded serum B12 level within the past 6 months were approached to have their serum B12 level tested. One hundred and sixty (61%) residents consented and their doctors were contacted for further consent. A total of 130 (50%) residents completed the study.
  
  
  METHODS
  Clinical and demographic characteristics, and serum B12 level.
  
  
  RESULTS
  Of the 130 residents tested, 18 residents (14%) were considered vitamin B12 deficient (serum level <150 pmol/L), 47 (36%) were equivocal (150 pmol/L to 250 pmol/L) and 65 (50%) had normal serum B12 levels (>250 pmol/L). There was a weak negative correlation between age and serum B12 level in those residents not taking a multivitamin (n=120, r=-0.19, p<0.05). The use of a multivitamin or antipsychotic drug were associated with altered mean serum B12 levels (+137 pmol/L, p<0.001 and -70 pmol/L, p<0.001 respectively).
  
  
  CONCLUSIONS
  As vitamin B12 deficiency can manifest in a range of symptoms that are frequently misdiagnosed, the finding of undetected deficiency in 14% of residents is a cause for concern. Oral multivitamin supplementation may help prevent deficiency, and potentially treat existing deficiencies in older institutionalised people.
authors.affiliation: Unit for Medication Outcomes Research and Education, School of Pharmacy, University of Tasmania, Hobart, Tasmania 7001, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Mirkazemi
authors.forename: G M
authors.initials: GM
authors.lastname: Peterson
authors.forename: P C
authors.initials: PC
authors.lastname: Tenni
authors.forename: S L
authors.initials: SL
authors.lastname: Jackson
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood; D001315:Australia; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D005260:Female; D006707:Homes for the Aged / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D009735:Nursing Homes; D015995:Prevalence; D012112:Residential Facilities; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000097:blood; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control
chemical_list: D014805:Vitamin B 12