Abstract
Eighty patients suffering from various anemic diseases were administered 50μg of vitamin B_<12> intramuscularly. The vitamin B_<12> levels of blood were determined, just before the injection and at 30 minutes, 1 and 3 hours after the injection by microbiological assay. These values were compared with those of normal subjects. (1) Normal subjects : In 30 minutes after injection, the level rose up to five or six times the initial one and showed maximum value. Three hours after injection, the level dropped to twice the initial value. (2) Iron deficiency anemia : Comparing with normal subjects, no significant differences were observed. (3) Myelogenous leukemia : Remarkable elevation in the level was observed after injection, and especially in chronic patients, the elevation was more marked. An abnormal binding of vitamin B_<12> with α-globulin in serum seemed to be the main factor of the elevation. (4) Aplastic anemia : In severe cases, marked elevation was observed. It might be caused by disturbed vitamin B_<12> consumption. (5) Liver cirrhosis : The degree of elevation in vitamin B_<12> level seemed to be parallel with the degree of liver dysfunction. (6) Pernicious anemia : No significant elevation was observed. (7) Anemia of infection : The elevation was hardly observed. (8) Nephrogenic anemia : No distinct relation was obtained. From these results, the author suggests that the vitamin B_<12> administration test is clinically useful for diagnosis of various anemias and also for the study of vitamin B_<12> metabolism, as the method is rather sensitive than the usual single blood level determination without vitamin B_<12> administration.
