Vitamin K absorption in the large intestine

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

SaintJude

Full Member
10+ Year Member
Joined
Jan 4, 2012
Messages
1,479
Reaction score
5
So Vitamin K is produced and absorbed in large intestine. Does removal of it cause issues with blood clotting? Or will there be compensatory mechanisms? Thought I might ask since Morsetlis is hanging around (Thanks a lot!--God-willing, I'll have an attending this helpful)

Members don't see this ad.
 
So Vitamin K is produced and absorbed in large intestine. Does removal of it cause issues with blood clotting? Or will there be compensatory mechanisms? Thought I might ask since Morsetlis is hanging around (Thanks a lot!--God-willing, I'll have an attending this helpful)

Vitamin K is necessary for the gamma-carboxylation of factors II, VII, IX and X, and proteins C and S. Vitamin K deficiency can produce a coagulopathy (warfarin (Coumadin) inhibits the same factors.) Administering vitamin K is one way to reverse the effects of Coumadin. Vitamin K deficiency can be caused by broad-spectrum antibiotics, which kill the bowel flora which normally produce vitamin K. The other source is leafy green vegetables. You would expect to see an elevated PT (INR) and normal PTT unless the coagulopathy is severe.
 
So Vitamin K is produced and absorbed in large intestine. Does removal of it cause issues with blood clotting? Or will there be compensatory mechanisms? Thought I might ask since Morsetlis is hanging around (Thanks a lot!--God-willing, I'll have an attending this helpful)

To answer your question in a more simplified form, yes, removal of Vitamin K will cause issues with blood clotting as it activates factors involved in the pathway of converting Fibrinogen to Fibrin which forms clots.
 
Vitamin K is necessary for the gamma-carboxylation of factors II, VII, IX and X, and proteins C and S. Vitamin K deficiency can produce a coagulopathy (warfarin (Coumadin) inhibits the same factors.) Administering vitamin K is one way to reverse the effects of Coumadin. Vitamin K deficiency can be caused by broad-spectrum antibiotics, which kill the bowel flora which normally produce vitamin K. The other source is leafy green vegetables. You would expect to see an elevated PT (INR) and normal PTT unless the coagulopathy is severe.

A bit too complicated for MCAT maybe...

Vitamin K helps with creation of clotting factors. It is produced by intestinal bacteria and also taken up in normal food. As with the other fat soluble vitamins (ADEK) think about vitamin deficiency due to intestinal damage, parasites, etc.

Some drugs inhibit the reduction of "used" Vit K to "fresh" Vit K. This prevents the usage of Vit K to generate carboxylated clotting factors. Since the epoxide reductase is not directly involved in clotting, fresh Vit K can be given to reverse the effects of warfarin.

I didn't encounter a single Vitamin question on the MCAT so the logic used here might be more important than actual facts.
 
Members don't see this ad :)
A bit too complicated for MCAT maybe...

Vitamin K helps with creation of clotting factors. It is produced by intestinal bacteria and also taken up in normal food. As with the other fat soluble vitamins (ADEK) think about vitamin deficiency due to intestinal damage, parasites, etc.

Some drugs inhibit the reduction of "used" Vit K to "fresh" Vit K. This prevents the usage of Vit K to generate carboxylated clotting factors. Since the epoxide reductase is not directly involved in clotting, fresh Vit K can be given to reverse the effects of warfarin.

I didn't encounter a single Vitamin question on the MCAT so the logic used here might be more important than actual facts.

This. The only thing you need to know about vitamins on the MCAT is that they are cofactors. It's just an undergrad class, but my A&P teacher didn't even talk about vitamins. Not important until you get to med school.
 
Lipophilic=ADEK

hydrophobic= everything else

It's easiest to use terms like water-soluble and fat-soluble so you don't trip yourself up like this...

I think you guys mean hydrophilic. Lipophilic=hydrophobic.

Hydrophilic = water soluble, hydrophobic (lipophilic) = fat soluble/water insoluble.
 
I meant exactly what I said.

He meant exactly what he meant, but not exactly what he said ;p
 
Top