Vitamin K Flashcards
Why was vitamin K given this name?
it is concerned with blood coagulation and comes from the Danish word “koagulation”
Who noted that chicks kept on ether-extracted diets became anemic and developed subcutaneous and intramuscular hemorrages?
Henrik Dam of Denmark
Where was vitamin K1 isolated from?
plants
Where was vitamin K2 isolated from?
fishoil
What is the most active form of vitamin K?
the synthetic form “menadione” (aka 2-methyl-1,4 naphthoquinone)
Sources of vitamin K
-fresh or dry green, leafy materials
-liver, egg, and fishmeal
What is required vit. K for its formation?
-prothrombin
-other plasma proteins in the liver needed for blood coagulation
Where do ruminants synthesize vitamin K?
in the rumen and intestines
Where do non-ruminants synthesize vitamin K?
in the intestines (except the chick)
What diet is deficient for chicks?
Corn-SBM diet (add 2% alfalfa meal and prevent)
What 2 antibiotics aggravate borderline deficiency situations by increasing prothrombin time more?
arsenicals and terramycin
What is the main symptom of deficiency of vit. K?
hemorraghic due to extension of blood coagulation time (normal time is about 1 minute)
Coprophagy
feces eating
What stalls attempts to study vit. K?
coprophagy
What causes rats to bleed to death internally?
dicoumarol caused by vit. K deficiency
