https://youtu.be/TNug0MHdhq0

Overview

• An autoimmune disorder affecting the gastric mucosa

• This results in Vitamin B12 deficiency anaemia

• Pernicious means that the Sx & Sx are often subtle and diagnose is often delayed.

• It is the most common cause of B12 deficency

  • Not the only cause

  Other causes of B12 deficiency

• Insufficient dietary intake
• Atrophic gastritis
  • (e.g. secondary to H. pylori infection)
• Gastrectomy
• Malnutrition - alcoholism
• Nitrous oxide induced (laughing gas)

Pathophysiology

• The parietal cells of the stomach produce a protein called intrinsic factor
  • Intrinsic factor is essential for the absorption of vitamin B12  in the ileum