vitamin B12 and folate

Question 1

Describe the absorption of B12

Answer 1

1: Food (meat/liver/eggs) travels to stomach

2:stomach acid splits B12 from food, B12 binds to haptocerrin
Stomach acid also causes intrinsic factor to be produced

3: B12 and haptocerrin travel to small bowel where proteases from pancreas split B12 from haptocerrin and B12 binds to intrinsic factor
4: B12 and intrinsic factor travel to terminal ileum and B12 is absorbed via cubulin receptors

Question 2

Describe the absorption of folate

Answer 2

1: food (leafy veg/yeast - destroyed by cooking) travels to stomach
2: dietary folate converted to monoglutamate and absorbed in duodenum and jejunum

Question 3

How long do body stores of B12 last vs Folate?

Answer 3

B12 - 2-4yrs

Folate - 4mths