Vitamin K deficiency
Deficiency of vitamin K, a fat-soluble vitamin, leads to a bleeding tendency.
Insufficient vitamin K intake or absorption. Sources of dietary vitamin K include vegetables, peas, beans and liver. Deficiency occurs in obstructive jaundice and certain malabsorption syndromes. Warfarin prevents the reduction of vitamin K to its active form leading to functional vitamin K deficiency.
Vitamin K is a co factor in the synthesis of clotting factors II (prothrombin), VII, IX and X. In its absence the factors do not have an active binding site and are there-fore functionally deficient. Vitamin K is also involved in producing proteins required for bone calcification.
Patients present with bruising, mucosal bleeding and haematuria.
The prothrombin time and the partial thromboplastin time are prolonged.
Vitamin K (phytomenadione) can be given as iv. or im injections. If given orally in malabsorption syndromes it must be in a water-soluble form.