3/12/2013

Vitamin K - clotting factor

Vitamins are:

Fat soluble (A, D, E and K) vitamins – are absorbed passively and must be transported with dietary lipid. They tend to be found in the lipid portions of the cell such as membranes and lipid droplets. They are excreted with the feces, via enterohepatic circulation.

Water soluble (ascorbic acid, folate, thiamin, riboflavin, niacin, pyridoxine, biotin, pantothenic acid, cobalamin) vitamins – are absorbed by passive and active mechanisms, transported by carriers, and not stored in appreciable amounts in the body. They are excreted in the urine.


Vitamin K plays a role in bone formation and regulation of multiple enzyme systems. 

Vitamin K is known as the clotting vitamin, because without it blood would not clot. Some studies suggest that it helps maintain strong bones in the elderly.

Vitamin K is essential for the posttranslation carboxylation of glutamic acid residues in proteins to form carboxyglutamate, the residues bind calcium. In the process of generating residues, vitamin K is oxidized to an epoxide. It is restored to its hydroquinone form by the enzyme expoxide reductase. 


Dietary reference intakes of vitamin K


Infants 2-2.5 mcg/day

Children 30-55 mcg/day

Adolescents 60-75 mcg/day

Adults 90-120 mcg/day

Pregnant 75-90 mcg/day

Lactating 75-90 mcg/day 



Vitamin K content of selected foods


Spinach, frozen, cooked, 1 cup (1027 mcg)

Broccoli, cooked, 1 cup (220 mcg)

Asparagus, cooked, 1 cup (144 mcg)

Cabbage, cooked, 1 cup (73 mcg)

Green beans, raw, 1 cup (47 mcg)

Carrot, raw, 1 cup (14 mcg)

Avocado, raw, 1 oz (6 mcg)

Ground beef, cooked, 3 oz (1 mcg) 



Symptoms of Vitamin K deficiency


Hemorrhage

Hypoprothrombinemia 



Signs of Vitamin D toxicity


Hemolytic anemia



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