Serum vitamin B12 in renal failure

Abstract
The serum vitamin B12 level was abnormally high in 14 out of 32 cases of renal failure. This was probably due to impaired excretion of the vitamin, but the results of measurements of the rate of excretion of radioactive vitamin B12 did not provide unequivocal evidence on this point; other possible explanations are discussed. Renal failure must be added to the causes of high serum B12 levels.