What is the recommended vitamin K (Vit K) dosage for newborns to prevent vitamin K deficiency bleeding?

Vitamin K Prophylaxis for Newborns

All newborn infants should receive a single intramuscular dose of 0.5 to 1.0 mg vitamin K1 within one hour of birth to prevent vitamin K deficiency bleeding (VKDB). 1, 2

Recommended Dosing Options

Primary Recommendation

• Intramuscular (IM) administration: 0.5 to 1.0 mg vitamin K1 as a single dose within one hour of birth 1, 2
  • This is the preferred route due to superior efficacy and reliability 3

Alternative Oral Regimens (if IM route declined)

• Option 1: 3 × 2 mg vitamin K1 orally at birth, at 4-6 days, and at 4-6 weeks 3
• Option 2: 2 mg vitamin K1 orally at birth, followed by weekly doses of 1 mg for 3 months 3
• Option 3: 2 mg oral dose at birth, followed by a second 2 mg oral dose between day 2-7 (for formula-fed infants only) 4

Special Populations

• Preterm infants:

  • Should receive 10 μg/kg/day of vitamin K if on parenteral nutrition 5
  • Oral route is not appropriate for preterm infants 3

• High-risk newborns (premature, birth asphyxia, difficult delivery, delayed feeding, hepatic disease):

  • First dose must be administered via IM or slow intravenous route 4
  • May require repeated doses based on clinical status 4

Risk Factors for Vitamin K Deficiency

• Exclusively breastfed infants (breast milk contains low vitamin K levels) 5, 6
• Infants whose mothers took medications that interfere with vitamin K metabolism (anticonvulsants, anticoagulants, antituberculosis drugs) 5
• Infants with underlying conditions such as cystic fibrosis, alpha-1-antitrypsin deficiency, or cholestasis 5
• For infants of mothers on vitamin K-inhibiting drugs, antenatal maternal prophylaxis (10-20 mg/day orally for 15-30 days before delivery) helps prevent early VKDB 4

Important Considerations

• The date, dose, and mode of administration should be documented 3
• If an infant vomits or regurgitates oral vitamin K within 1 hour, the dose should be repeated 3
• Oral administration is not appropriate for infants with cholestasis, impaired intestinal absorption, or those too unwell to take oral medication 3
• Success of oral prophylaxis depends on compliance with the protocol, which varies between populations and healthcare settings 3, 6
• Parental refusal of vitamin K prophylaxis should be documented due to the risk of late VKDB 3
• Parental education about the importance of vitamin K prophylaxis may improve compliance 3

Monitoring

• Classical coagulation tests (PT, PTT) can be used in low-risk infants for indirect evaluation of vitamin K status 5
• Undercarboxylated Serum Vitamin K-Dependent Proteins (PIVKA-II) are more useful biomarkers of subclinical vitamin K deficiency for at-risk patients 5
• A prompt response (shortening of prothrombin time in 2-4 hours) following vitamin K administration is usually diagnostic of hemorrhagic disease of the newborn 2