Cobalamin (vitamin B12)

In the diet:

5-15 pg/day (min. 1-5)

B12

Protein

HC

pH t

B12

Duodenum

Stomach

1

B12

R-protein

Protein

From saliva

R-protein

Intrinsic factor

Pancreas

B12

R-Protein

Trypsin

B12

Terminal ileum

B12

IF

2

Specific binding to receptors of ileal mucosa

B12

IF

B12

pH > 5.6

Transcellular

#B12 transport (~1-2 ug/day)

TC III

3

Plasma

Liver

Storage

TC II

TCI

Plasma-

"reserve"

Cell metabolism

Excretion