What is the recommended route and dose of vitamin K (Vit K) administration for patients, including newborns and adults with various medical conditions, such as liver disease or bleeding disorders?

How to Give Vitamin K

For all newborns, administer 0.5-1.0 mg of vitamin K1 intramuscularly within one hour of birth—this is the gold standard and most reliable method to prevent all forms of vitamin K deficiency bleeding. 1, 2, 3

Newborns (Term, Healthy)

Intramuscular Route (Preferred)

• Give 0.5-1.0 mg vitamin K1 IM within one hour of birth 1, 2, 3
• This single dose effectively prevents early, classic, and late vitamin K deficiency bleeding (VKDB) 4, 5
• The intramuscular route is preferred for efficiency and reliability of administration 3

Oral Route (Alternative if Parents Refuse IM)

If parents decline intramuscular administration after adequate counseling about increased bleeding risk, use one of these oral regimens:

Option 1: 1, 3

• 2 mg at birth
• 2 mg at 4-6 days
• 2 mg at 4-6 weeks

Option 2: 1, 3

• 2 mg at birth
• Then 1 mg weekly for 3 months (12 weeks total)

Critical caveat: Oral vitamin K is less effective than IM for preventing late VKDB 4, 5. If the infant vomits or regurgitates within 1 hour of administration, repeat the oral dose 3. Document parental refusal of IM administration due to the risk of late VKDB 3.

Preterm Infants

• Give 10 μg/kg/day of vitamin K1 for infants on parenteral nutrition 1, 6, 7
• The oral route is NOT appropriate for preterm infants 3
• Doses should be repeated, particularly in premature infants, with route determined by clinical state 4

High-Risk Newborns

For infants at elevated risk (premature, birth asphyxia, difficult delivery, delayed feeding, hepatic disease, maternal drugs inhibiting vitamin K), the initial dose must be given IM or slow IV 1, 4. High-risk conditions include:

• Cholestasis or impaired intestinal absorption 3
• Infants too unwell to take oral vitamin K 3
• Maternal anticonvulsants, anticoagulants, or antituberculosis drugs 6, 7
• Cystic fibrosis, alpha-1-antitrypsin deficiency 6, 7

Adults

Routine Supplementation

• Daily dose: 1-10 mg/day depending on age and risk factors 1
• For adults on parenteral nutrition: 200 μg/day 6

Treatment of Deficiency or Anticoagulant Reversal

• Initial dose: 2.5-10 mg, up to 25 mg for most indications 1, 2
• Rarely, 50 mg may be required for severe deficiency 2
• Maximum effect for IV administration: 6-12 hours 8, 6
• Oral supplementation takes approximately 24 hours to reach full effect 8, 6

Route Selection for Adults

• IV administration should be given slowly due to rare anaphylactoid reactions (bronchospasm, cardiac arrest) 8, 6
• Subcutaneous or intramuscular routes are alternatives 2
• If prothrombin time has not shortened satisfactorily in 6-8 hours after parenteral administration, repeat the dose 2

Special Populations

Cystic Fibrosis

• Infants: 0.3-1.0 mg/day 1, 6
• Older children and adults: 1-10 mg/day depending on age 6
• Daily administration is preferred due to low storage capacity of vitamin K 6
• Monitor vitamin K status regularly 6

Exclusively Breastfed Infants

• Must receive prophylaxis at birth 1, 7
• Require continued supplementation if oral route chosen, as breast milk contains low levels of vitamin K 6, 7

Patients on Anticoagulants

• Monitor coagulation parameters when vitamin K is administered 6
• Patients should avoid making major sudden changes in vitamin K intake 8
• Continuous enteral nutrition should be withheld for 1 hour before and after anticoagulant drug administration to prevent interactions 8, 6

Monitoring

• For newborns with suspected VKDB: A prompt shortening of prothrombin time within 2-4 hours after vitamin K administration is diagnostic 1, 7
• For at-risk patients: PIVKA-II (undercarboxylated vitamin K-dependent proteins) is the preferred biomarker when available 1, 6, 7
• Classical coagulation tests (PT, PTT) can be used in low-risk infants but are not specific to vitamin K deficiency 7

Safety Considerations

• Vitamin K1 (phylloquinone) has no known adverse effects or toxicity concerns with supplementation 1, 6, 7
• Rare anaphylactoid reactions have been reported with IV vitamin K1 administration 8, 6
• Use preservative-free diluents for IV administration in newborns, as benzyl alcohol has been associated with toxicity 2
• When dilutions are indicated, start administration immediately after mixing and discard unused portions 2