Coeliac Disease (adults)
- Vitamin B12 levels should be measured at time of diagnosis of Coeliac Disease.
- Low B12 levels are likely to be secondary to malabsorption and should improve with gluten exclusion. However, Intrinsic Factor should be checked (done automatically by labs if B12 low) and an assessment made to exclude pernicious anaemia, as a small number of people will have a dual diagnosis, not surprising as both are autoimmune conditions.
- In adults it is prudent to give intramuscular replacement initially, but then move to oral, or no, B12 supplementation once the anti-tTG has normalised.
- A small number of patients will have ongoing poor dietary compliance, with high anti-tTG, and may need ongoing supplementation, some by injection.
Coeliac Disease (Paediatrics)
- Vitamin B12 levels should be measured at time of diagnosis of Coeliac Disease.
- Low B12 levels are likely to be secondary to malabsorption and should improve with gluten exclusion. However, Intrinsic Factor should be checked (done automatically by lab if B12 low) and an assessment made to exclude pernicious anaemia, as a small number of people will have a dual diagnosis, not surprising as both are autoimmune conditions.
- Lothian GI experience is that most results will be normal, and low in very few children with a new diagnosis.
- In children, with a few exceptions (see below) oral B12 supplements should be sufficient.
- Vitamin B12 levels are re-measured at a year from diagnosis, and if normal, and there is good control and low anti-tTG antibody levels, then generally B12 supplementation can be stopped.
- A small number of patients will have ongoing poor dietary compliance, with high anti-tTG, and may need ongoing supplementation, some by injection.
- In children especially all these assessments and decisions would be made by the specialist GI service, and the GP advised accordingly.
Gastrointestinal Surgery
- Both gastrectomy and bariatric surgery can lead to B12 deficiency and require regular monitoring and replacement if levels are falling despite good dietary intake. Oral replacement is often inadequate in these patients since the cause is likely malabsorption.
- Patients who have undergone gastric bypass will require 3 monthly intramuscular injections of vitamin B12.
- Patients who have undergone sleeve gastrectomy surgery or duodenal switch are usually recommended to have initial 3 monthly intramuscular injections of vitamin B12 but may need less frequent injections depending on blood results, however, they should always be given IM rather than oral treatment.
- Terminal ileum resection is an indication for lifelong intramuscular B12 replacement.
