What are the guidelines for administering vitamin K (Vit K) intramuscularly (IM) to newborns?

Guidelines for Newborn Vitamin K Intramuscular Administration

All newborn infants should receive a single intramuscular dose of 0.5 to 1.0 mg vitamin K1 within one hour of birth as the preferred route for prophylaxis against vitamin K deficiency bleeding (VKDB). 1, 2

Recommended Administration Protocol

• The American Academy of Pediatrics recommends a single intramuscular (IM) dose of 0.5 to 1.0 mg vitamin K1 for newborns within one hour of birth 1
• The IM route is considered the preferred method for efficiency and reliability of administration 2
• The date, dose, and mode of administration should be documented in the medical record 2
• Parental refusal of vitamin K prophylaxis should be documented due to the risk of late VKDB 2

Alternative Oral Administration Options

If parents decline IM administration, oral vitamin K can be offered with clear documentation of the increased risks:

• Option 1: 3 × 2 mg vitamin K1 orally at birth, at 4 to 6 days, and at 4 to 6 weeks 2
• Option 2: 2 mg vitamin K1 orally at birth, followed by a weekly dose of 1 mg orally for 3 months 2
• The oral route is less effective than IM administration for preventing late VKDB 3, 4
• If the infant vomits or regurgitates within 1 hour of oral administration, repeating the dose may be appropriate 2

Special Considerations

• The oral route is not appropriate for:

  • Preterm infants 2
  • Newborns with cholestasis or impaired intestinal absorption 2
  • Infants too unwell to take oral vitamin K1 2
  • Infants whose mothers have taken medications that interfere with vitamin K metabolism (anticonvulsants, anticoagulants, antituberculosis drugs) 2, 5

• Preterm infants on parenteral nutrition should receive 10 μg/kg/day of vitamin K 5

Monitoring and Risk Assessment

• 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 a more useful biomarker of subclinical vitamin K deficiency for at-risk patient groups 5, 6
• Risk factors for vitamin K deficiency include:
  • Exclusively breastfed infants (breast milk contains low levels of vitamin K) 5, 6
  • Infants whose mothers have taken medications that interfere with vitamin K metabolism 5
  • Infants with underlying diseases such as cystic fibrosis, alpha-1-antitrypsin deficiency, or cholestasis 5

Recent Evidence and Considerations

• Recent research suggests that oral supplementation of vitamin K1 after discharge significantly reduced PIVKA-II concentrations in exclusively breastfed term infants 6
• A 2025 randomized controlled trial found no significant difference in PIVKA-II levels between neonates receiving 1 mg versus 2 mg vitamin K IM, suggesting a similar risk for late-onset VKDB in both groups 7
• For formula-fed neonates without risk of hemorrhage, a 2 mg oral dose at birth followed by a second 2 mg oral dose between day 2 and 7 may be sufficient 3
• For exclusively breastfed infants, continued supplementation after initial doses is recommended until completion of breastfeeding 3

Common Pitfalls and Caveats

• Failure to document parental refusal of vitamin K prophylaxis 2
• Using oral administration in situations where it's contraindicated (preterm infants, cholestasis, etc.) 2
• Not repeating oral doses when the infant vomits or regurgitates shortly after administration 2
• Inadequate follow-up for infants receiving oral vitamin K regimens, which require multiple doses and depend on parental compliance 2, 3
• Not providing prenatal education about the importance of vitamin K prophylaxis, which may improve compliance 2