Vitamin B12 absorption in patients with ileal conduits.

The absorption of vitamin B12 was assessed using the 58Co-absorption test (Schilling test) in 39 patients in whom ileal loops had been used as urinary diversion after excision of the bladder for transitional cell carcinoma. 29% of the patients were found to absorb less than 12% of the offered dose of labelled vitamin B12 after excluding gastric-mediated malabsorption by the modified Schilling test. Examination of haemoglobin, MCV or vitamin B12 in the peripheral blood gave unreliable indications of the absorptive ability of these patients.