Influence of continent ileal urinary diversion on vitamin B12 absorption.

Abstract

Because vitamin B12 is mainly absorbed in the terminal ileum, we evaluated potential absorption deficiencies in continent ileal reservoirs. Eight to 25 months (mean 13) after surgery we evaluated 25 patients with a Kock pouch and 29 with an ileal neobladder. A Schilling test and red blood count were done, and serum levels of vitamin B12 and folic acid were determined. Absorptive capacity was decreased in 20 of the 25 Kock pouch patients but none of the 29 ileal neobladder patients. Four patients in each group had low vitamin B12 levels. No patient had megaloblastic anemia. Folic acid levels were normal in all patients. A loss of 50 cm. of terminal ileum seems to be the critical margin sufficient vitamin B12 absorption.