Describe the digestive processes required for vitamin B12 absorption.

Describe the digestive processes required for vitamin B12 absorption.

• A. B12 is released in the stomach and binds intrinsic factor in the stomach, then absorbed in the colon.
• B. Gastric acid releases B12 from dietary proteins; B12 then binds to R-proteins in the stomach and intrinsic factor, enabling absorption in the terminal ileum.
• C. B12 is absorbed in the duodenum independently of intrinsic factor.
• D. B12 absorption occurs in the jejunum via passive diffusion.

Answer: (B)