title: Clinical correlates of subnormal vitamin B12 levels in patients infected with the human immunodeficiency virus.
abstract: OBJECTIVE
  To determine the prevalence and describe the clinical correlates of subnormal cobalamin levels in subjects infected with the human immunodeficiency virus (HIV), and to assess its relationship to virus-mediated immunosuppression and/or anti-viral therapy.
  
  
  METHODS
  Outpatient referral clinic in tertiary care hospital.
  
  
  METHODS
  200 HIV infected individuals.
  
  
  METHODS
  Descriptive cross sectional survey, with prospective follow-up in a subgroup of patients before and after initiation of zidovudine therapy.
  
  
  METHODS
  Routine complete blood count, serum B12 assay, CD4 counts. Serum homocysteine levels, and Schilling tests were performed on subgroups of study subjects.
  
  
  RESULTS
  Subnormal serum B12 levels were found in 61 subjects (30.5%). B12 deficient subjects were more likely to be taking zidovudine. (P = .007). Serum homocysteine levels were significantly higher in patients with subnormal cobalamin levels but were unrelated to CD4 counts or zidovudine use, and were rarely outside of the normal range. Malabsorption of vitamin B12 as evidenced by abnormal Schilling tests was more likely among patients with more advanced HIV disease, or gastrointestinal symptoms but was not necessarily associated with low B12 levels.
  
  
  CONCLUSIONS
  Decreased cobalamin levels are found frequently in HIV disease, especially among those treated with zidovudine. Evidence of B12 malabsorption is found among those with more advanced disease and gastrointestinal symptoms.
authors.affiliation: Department of Medicine, Montreal General Hospital, McGill University, Quebec, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Paltiel
authors.forename: J
authors.initials: J
authors.lastname: Falutz
authors.forename: M
authors.initials: M
authors.lastname: Veilleux
authors.forename: D S
authors.initials: DS
authors.lastname: Rosenblatt
authors.forename: K
authors.initials: K
authors.lastname: Gordon
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000188:drug therapy / Q000378:metabolism*; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014805:Vitamin B 12 / Q000097:blood*; D015215:Zidovudine / Q000627:therapeutic use
chemical_list: D015703:Antigens, CD; D015215:Zidovudine; D014805:Vitamin B 12