J Pouch and Vitamin B12 Deficiency

It is very common for patients with ileo-anal pouch (J Pouch) to suffer with B12 deficiency but this may not be picked up by routine blood tests

Vitamin B12 is absorbed in the end ileum, which in the case of J pouch patients has been removed. It is therefore very common for J pouch patients to suffer from Vitamin B12 deficiency. 

Unfortunately, routine blood tests to show B12 deficiency can be unreliable as described in the NHS paper on the subject:  Click on the link below.

NHS Diagnosis: Vitamin B12 or folate deficiency anaemia

In particular, this paper explains that

  • A particular drawback of testing vitamin B12 levels is that the current widely used blood test only measures the total amount of vitamin B12 in the blood
  • This means it measures forms of vitamin B12 that are “active” and can be used by the body, as well as the bound or “inactive” forms, which cannot be used by the body
  • If a significant amount of the vitamin B12 in the patient’s blood is inactive, a blood test may show normal B12 levels, even though the patient  cannot use much of it and might have Vitamin  B12 deficiency
  • This is why it’s important for symptoms to be taken into account when a diagnosis is made.
Signs and symptoms of Vitamin B12 deficiency

See also Vitamin B12 deficiency following restorative proctocolectomy

In summary, it is recommended that if a patient with a J Pouch presents with relevant symptoms, they might well benefit from B12 supplements (usually in the form of B12 injections), even if blood test results show the B12 level is within the normal range. 

Pouch B12 deficiency for GPs
Pouch B12 deficiency for GPs

B12 deficiency is common amongst patients with ileo-anal pouch. However, the routine blood test to check for B12 deficiency is unreliable. This document, produced by the Pouch Nurses at St. Mark’s Hospital London, explains why the blood test may be unreliable and can be shown to a GP if you feel you have the relevant symptoms.

Medic Alert Card

We have also updated the Medic Alert information on our website to provide a full explanation of this B12 deficiency phenomenon. The medic alert page contains a comprehensive description of what ileo-anal pouch surgery involves and the issues and challenges faced by people living with an ileo-anal pouch. The reality is that ileo-anal pouch surgery is performed relatively rarely, and its possible that you may be the only pouch patient registered with your GP practice. It is understandable that you may know more about the procedure than your GP, and therefore you may both benefit if you share this information with him/her!

If you are a Red Lion Group member, you should have a “Can’t wait / Medic alert card“, which has a QR code which links to the medic alert information.

The Medic Alert online information and a downloadable copy can be found at or by scanning the QR code on the card.

The Medic Alert information has been created by the Red Lion Group, with support from the Pouch nurses and Consultants at St. Mark’s Hospital the UK National Bowel hospital and pioneers in the field of the ileo-anal-pouch.

For further information about the Red Lion Group “Can’t Wait / Medic Alert” card click here.

Gary Bronziet