Vitamin B12 in Plasma in Patients with Continent Ileostomy and Long Observation Time

Plasma cobalamins (vitamin B₁₂) were determined by a microbiological method in 235 patients with continent ileostomies and postoperative observation times of 3–13 years (mean. 6 years). The influence of the reservoir on the vitamin B₁₂ values could not be evaluated in 22 patients (9%)—because of prophylactic treatment in 6%, subnormal B₁₂ values before the operation in 1%, and ‘treatment’ of various neurological symptoms not caused by vitamin B₁₂ deficiency in 2%. Fourteen (7%) of the remaining 213 patients had developed subnormal plasma levels of vitamin B₁₂ and another 14 patients (7%) had ‘borderline’ values (130–200 pmol/l). The median time interval between reservoir operation and the development of subnormal values was 7.5 years (range, 3–11 years). A small-bowel resection had been added to the proctocolectomy in 11 out of 14 patients with subnormal values and in 8 out of 14 patients with borderline values. Subnormal or borderline values were seen in 27% of patients with Crohn's disease and in 12% of patients with ulcerative colitis. No patient had anaemia or neurological symptoms caused by B₁₂ deficiency. The study shows that most patients with continent ileostomies do not develop B₁₂ deficiency, and there is therefore no need for general prophylaxis. Since at least 7% developed subnormal values, the plasma levels of vitamin B₁₂ should, however, be followed up regularly in all patients with continent ileostomies.