What is the purpose of vitamin K (Vit K) administration?

Purpose of Vitamin K Administration

Vitamin K is administered primarily to prevent and treat bleeding disorders caused by deficiency of vitamin K-dependent clotting factors (II, VII, IX, and X), with the most critical application being prevention of life-threatening hemorrhage in newborns and reversal of anticoagulant-induced coagulopathy. 1

Primary Clinical Indications

Newborn Prophylaxis and Treatment

• All newborns should receive vitamin K at birth to prevent vitamin K deficiency bleeding (VKDB), which can cause devastating intracranial hemorrhage and death 2, 3
• Newborns have physiologically low levels of vitamin K-dependent clotting factors compared to adults, making them inherently vulnerable to bleeding disorders 2
• Three forms of VKDB exist: early (0-24 hours), classic (1-7 days), and late (2-12 weeks), with late VKDB carrying the highest risk of intracranial hemorrhage 4, 3
• Exclusively breastfed infants are at particularly high risk because breast milk contains very low concentrations of vitamin K 2, 5

Anticoagulant Reversal

• For warfarin-associated intracranial hemorrhage, vitamin K 10 mg IV should be administered immediately along with prothrombin complex concentrates to ensure durable INR reversal 6
• The maximum effect of IV vitamin K occurs at 6-12 hours, while oral administration takes approximately 24 hours 6
• If INR remains elevated ≥1.4 within 24-48 hours after initial reversal, redose with vitamin K 10 mg IV 6
• Vitamin K is essential for sustained reversal because it enables hepatic synthesis of clotting factors, whereas factor concentrates provide only temporary correction 6

Malabsorption and Cholestatic Conditions

• Vitamin K administration is indicated for conditions causing fat malabsorption, including celiac disease, cystic fibrosis, short bowel syndrome, obstructive jaundice, biliary fistula, sprue, ulcerative colitis, and intestinal resection 1
• Parenteral vitamin K is specifically recommended for patients with decompensated liver disease who are jaundiced or have cholestatic liver disease 7
• Vitamin K status should be measured in at-risk patients with steatorrhea, prolonged broad-spectrum antibiotic use, and chronic kidney disease 6

Drug-Induced Deficiency

• Vitamin K treats hypoprothrombinemia caused by antibacterial therapy and drugs interfering with vitamin K metabolism, including anticonvulsants, salicylates, and antituberculosis medications 1, 4

Mechanism and Rationale

• Vitamin K is essential for hepatic synthesis of clotting factors II, VII, IX, and X 1
• Deficiency results in prolonged prothrombin time with impaired clotting or frank bleeding, confirmed by response to vitamin K administration 6
• Beyond hemostasis, vitamin K deficiency contributes to poor bone development, osteoporosis, and increased cardiovascular disease risk 6
• Vitamin K may exert anti-inflammatory effects by suppressing NF-κB signal transduction 6

Important Safety Considerations

Administration Routes and Timing

• IV administration should be by slow injection to minimize risk of rare anaphylactoid reactions (3 per 100,000 doses) that can cause bronchospasm and cardiac arrest 7
• For newborns at high risk of hemorrhage (prematurity, birth asphyxia, difficult delivery, maternal anticoagulant use), the first dose must be IM or slow IV 4
• Oral vitamin K protects against early and classic VKDB but is less effective than IM prophylaxis for preventing late VKDB 4

Dosing Pitfalls

• Never exceed 10 mg per dose, as higher doses can create a prothrombotic state and prevent re-anticoagulation for days 7
• The synthetic vitamin K3 (menadione) is extremely toxic and no longer available due to risk of jaundice, hemolytic anemia, and kernicterus in infants 6
• Vitamin K1 (phytonadione) and K2 are not associated with toxicity 6

Drug Interactions

• Patients on anti-vitamin K drugs should avoid sudden major changes in vitamin K intake and require monitoring with blood clotting tests 6
• Continuous enteral nutrition should be withheld for 1 hour before and after anticoagulant drug administration to prevent interactions 6

When NOT to Administer

• Avoid vitamin K reversal when intracranial hemorrhage is suspected due to cerebral venous thrombosis, as reversal may worsen thrombosis 6
• Assess risks versus benefits carefully in patients with concurrent symptomatic thrombosis, ischemia, heparin-induced thrombocytopenia, or DIC 6
• In liver disease without cholestasis, vitamin K has minimal efficacy because the liver cannot synthesize clotting factors despite adequate vitamin K 7