Clinical Spectrum and Diagnosis of Cobalamin Deficiency [See Comments]

Abstract

To better estimate how frequently patients with low serum cobalamin (Cbl) levels in current clinical practice are truly deficient in Cbl and to determine the incidence of atypical or nonclassic presentations of Cbl deficiency, we prospectively studied 300 unselected consecutive patients with serum Cbl concentrations less than 200 pg/mL seen at two medical centers over a 2-year period. Baseline hematologic, neuropsychiatric, and biochemical measurements were obtained, followed by a course of parenteral Cbl ther…