Rejected at 2:49 p.m. Jul, 02, 2026 ] by schralp
Author: sumanth
Related Note: 1478898326485 5
Rationale for change

Vitamin B12 in food is bound to proteins, and its liberation begins in the mouth and stomach. Salivary glands secrete haptocorrin (also called R-binder or transcobalamin I), but the actual liberation of B12 from dietary proteins is primarily driven by:

Gastric acid (HCl) and pepsin in the stomach, which denature the proteins and release B12
Once free, B12 binds to haptocorrin (from saliva) in the acidic stomach environment, protecting it from degradation
In the duodenum, pancreatic proteases degrade haptocorrin, allowing B12 to bind to intrinsic factor (from gastric parietal cells) for absorption in the terminal ileum

So to be precise: salivary haptocorrin doesn't liberate B12 — it binds B12 after it's been liberated by stomach acid and pepsin. The liberation step is gastric, not salivary.

Rejection reason

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