Malabsorption of Crystalline Vitamin B12in Cystic Fibrosis

THE malabsorption of crystalline vitamin B12 has been documented both in pancreatic injury associated with alcohol abuse in the adult1 2 3 and after partial pancreatic extirpation in the rat.4 It was of interest, therefore, to study vitamin B12 absorption in cystic fibrosis since severe insufficiency of the exocrine pancreas is generally observed in this disease.5 Methods and MaterialsThe methods were similar to those previously reported3 except for the dose of radioactive 57Co-labeled vitamin B12, which was reduced to 0.25 μCi in 0.5 μg of unlabeled vitamin B12. The diagnosis of cystic fibrosis was established . . .