Treatment of Vitamin B12 Deficiency Anemia in Coeliac Disease and Gastric Malabsorption
When vitamin B12 deficiency anemia is driven by impaired absorption — particularly in patients with coeliac disease — ongoing replacement is required to correct the deficit and prevent relapse.
This protocol covers B12 deficiency secondary to coeliac disease, or to anatomical disruption of B12 absorption, including partial gastrectomy, terminal ileal resection, and Roux-en-Y gastric bypass.
Management involves intramuscular B12 replacement — with self-administration supported where clinically feasible — alongside an oral alternative for patients in whom injection is not appropriate, and dietary guidance on B12 intake.
Symptoms may improve within 2 weeks up to 3 months. A prompt rise in haemoglobin level is the expected early marker of adequate response.
- OTHER GASTRIC CAUSES OF MALABSORPTION: e.g. coeliac disease, partial gastrectomy or terminal ileal resection, Roux-en-Y gastric bypass.
- IM hydroxocobalamin — promote self-administration where possible.
- Oral cyanocobalamin only if IM is clinically inappropriate.
- With dietary advice to increase intake of foods rich in vitamin B12.
- Advise patients that symptoms may improve within 2 weeks up to 3 months and may initially get worse but should improve with time.
- If there is a failure to respond to therapy i.e. there is not a prompt rise in Hb level.