Vitamin metabolism in patients with a Mainz pouch I: long-term followup

We assessed whether creation of the Mainz pouch I, which requires 24 to 36 cm. of terminal ileum and 12 cm. of ascending colon including the ileocecal valve, leads to metabolic disturbances.

In 137 patients the levels of vitamins A, B1, B2, B6, B12, D and E, folic and bile acids, ammonia, and intracorpuscular vitamin B12 and folic acid were evaluated and a red blood count was performed. Patients were divided into children and adults, and into 3 groups according to number of years after surgery (2 or less, more than 2 to 4 and more than 4).

In all patients the levels of vitamins A, B1, B2, B6, D and E, folic and bile acids, and ammonia as well as red blood count were within normal ranges. In the 51 children there was no significant decrease in vitamin B12 postoperatively. In the 86 adults mean serum vitamin B12 plus or minus standard deviation decreased significantly from 402 +/- 182 ng./l. during the first 2 years postoperatively to 292 +/- 204 ng./l. after year 4 (normal 240 to 1,100). There was no significant decrease in intracorpuscular vitamin B12 during this period.

In addition to regular examinations, the determination of vitamin B12 levels 4 years after Mainz pouch diversion is mandatory. It remains unclear whether substitution is necessary. However, substitution is easy to achieve and even less expensive than the regular determination of vitamin B12.