[The diagnosis of vitamin B 12 deficiency].

In 5 normal persons, 1 patient with pernicious anemia, 5 patients with renal insufficiency in the state of compensation, and in one patient with chronic hemodialysis Schilling tests, activity of 57Co and vitamin B12 serum levels were measured. It was obvicous that activity of 57Co in serum 8 hours after oral application of 0.5 muCi 57Co-vitamin B12 showed reliable results to clear the problem of vitamin B12 malresorption. This method is easier than the Schilling test because the collection of 24-hour-urine is not necessary and an insufficiency of renal function does not influence the result.