Background: Because vitamin B,, is absorbed exclusively by the terminal ileum, we investigated vitamin B,, deficiency as a potential metabolic complication after urinary intestinal diversion.
Methods:We measured serum levels in patients with Kock pouches (n = 35); Indiana pouches ( t i = 27); and ileal conduits (n = 25). Serial determinations of serum BIL levels were obtained in 19 patients with Kock pouches and 14 patients with Indiana pouches. The dual-isotope Schilling test was performed in 9 patients with Kock pouches and 6 patients with Indiana pouches.Results: N o patient had an abnormally low serum BIL level (< 200 pdmL). Mean (f SD) serum B,, levels in patients with the Kock pouch (506 f 202 pg/mL) and the Indiana pouch (536 f 249 pg/mL) were lower than that in patients with the ileal conduit (727 f 391 pg/mL). The mean serum B,, level was not significantly different between patients with and without preoperative irradiation. Serial determinations showed that serum B,, levels in some patients with continent urinary reservoirs were persistently near the lower normal limit, or became progressively lower. Three of the 9 patients (33%) with Kock pouches and 4 of the 6 patients (67%) with Indiana pouches were B,, malabsorbers, although no patients had megaloblastic anemia or neurologic symptoms.Conclusions: Some patients with continent urinary reservoirs are at risk for vitamin B,? deficiency due to malabsorption. Routine evaluation of serum B,, levels is recommended for all patients with continent urinary reservoirs, and a Schilling test for those with subnormal serum B,, levels.Int