Comparative Study of Vitamin B 12 Assay in Urine

Abstract

Summary

The response of Ochromonas malhamensis, Euglena gracilis, and Lactobacillus leichmannii to vit. B₁₂ in normal urine and in urine of patients, given an intramuscular dose of 50 μg of vit. B₁₂ was studied. The “true” vit. B₁₂ values presumably are given by the Ochromonas malhamensis assay. The response of E. gracilis and L, leichmannii to other members of the B₁₂ group and to other metabolites is discussed from the standpoint of how to estimate responses other than O. malhamensis-active B₁₂. Calculations are given for the estimation of interfering metabolites.