Clinical correlates of subnormal vitamin B12 levels in patients infected
with the human immunodeficiency virus.
American journal of hematology; VOL: 49 (4); p. 318-22
Paltiel O; Falutz J; Veilleux M; Rosenblatt DS; Gordon K
OBJECTIVES: 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. SETTING: Outpatient referral clinic in tertiary
care hospital. PATIENT POPULATION: 200 HIV infected individuals. STUDY
DESIGN: Descriptive cross sectional survey, with prospective follow-up
in a subgroup of patients before and after initiation of zidovudine therapy.
MEASURES: 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.