Blood, 1952, Vol. 7, No. 2, pp. 243-250.
© 1952 American Society of Hematology, Inc.
Urinary Excretion of Vitamin B12
MARTIN F. SOKOLOFF A.B., M.S.1,
EVERETT H. SANNEMAN JR. M.D.1, and
MARION F. BEARD A.B., M.D.1
1 Institute for Medical Research, University of Louisville School of Medicine.
1. Twelve patients, 6 with pernicious anemia and 6 without pernicious anemia
as controls, were studied as to urinary excretion of vitamin B12.*
2. Microbiologic tube assay using Lactobacillus leichmanii A.T.C.C. # 4797
was the method of B12 assay.
3. Dosages used were 42.2, 63.3, 84.4, 211.0 µg given both in ascending and
descending order at daily intervals.
4. Amounts of 84.4 to 211.0 µg of vitamin B12 parenterally resulted invariably
in the excretion of 53 to 68 per cent of the injected vitamin B12 within 18 hours.
The percentage of excretion rose remarkably as the dosage increased.
5. An amount of 42.2 µg of vitamin B12 parenterally resulted in relatively
little excretion when this was the initial dose, but the excretion was appreciable
when these doses followed the injection of the larger doses. "Saturation" of the
body apparently occurs. In general more vitamimi B12 is excreted in the smaller
doses if these follow the larger doses.
6. No significant differences could be detected between the pernicious anemia
and nonpernicious anemia patients.
7. A possible explanation of these results is proposed.
Submitted on July 18, 1951
Accepted on October 1, 1951
