Digestion, Absorption, & Handling of Vitamin B12 (Cobalamin)

The video explains the structure, digestion, absorption, and handling of Vitamin B12, also known as cobalamin. It highlights the essential nature of B12, its complex digestion process involving proteins like pepsin, haptocorrin, intrinsic factor, and transcobalamin, and the reasons for its careful handling due to its large size and unstable bonds. The video emphasizes the importance of dietary intake of B12, as it is not synthesized by humans.

What is the primary source of vitamin B12 for humans?

• Fruits and vegetables

• Nuts and seeds

• Animal proteins

• Grains and cereals

Why is it important to protect vitamin B12 from stomach acid?

• It enhances the taste of food

• It prevents the breakdown of acid-labile bonds

• It helps in the digestion of proteins

• It increases the absorption rate

Which protein initially binds to vitamin B12 in the stomach?

• Haptocorrin

• Intrinsic factor

• Pepsin

• Transcobalamin

What role does trypsin play in the absorption of vitamin B12?

• It synthesizes B12 in the intestines

• It transports B12 to the liver

• It degrades haptocorrin to release B12

• It binds B12 to intrinsic factor

How is vitamin B12 transported to the liver?

• Free in the bloodstream

• Attached to pepsin

• Bound to transcobalamin

• Bound to intrinsic factor

Why is vitamin B12 handling in the body considered rigorous?

• It has unstable bonds and is essential

• It is synthesized by the human body

• It is easily absorbed without assistance

• It is a small and simple molecule

What is the main distribution center for vitamin B12 in the body?

• The stomach

• The small intestine

• The liver

• The pancreas