Bleeding disorders associated with vitamin K deficiency
Bleeding disorders associated with vitamin K deficiency Updated: 07/25/2023 © Jun Wang, MD, PhD General features Bleeding disorders due to nutritional vitamin K deficiency or warfarin use Clinical presentations History of nutritional deficiency or warfarin use Easy bruising Soft tissue hematoma Other bleeding symptoms Key risk factors Fat malabsorption syndromes (vitamin K is a fat soluble vitamin) Malnutrition Antibiotics (destroy bacteria producing vitamin K or interfere with vitamin K carboxylation) Newborn: Lack of VK in breast milk, or malabsorption caused by cholestasis, etc Warfarin associated inhibition of regeneration of the active form of vitamin K For Warfarin using patients: > 65, other conditions (atrial fibrillation, GI bleeding, cerebrovascular disease, etc), concomitant medications (aspirin, amiodarone) Key pathogenesis Impaired production of active factors II, VII, IX and X and proteins C and S Warfarin inhibits vitamin K reductas...