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

Vitamin K Dosage for Newborns to Prevent Vitamin K Deficiency Bleeding

All newborn infants should receive 1 mg of vitamin K1 by intramuscular injection at birth to prevent vitamin K deficiency bleeding (VKDB). 1

Recommended Dosage Regimens

The administration of vitamin K to newborns is essential to prevent VKDB, which can lead to life-threatening complications including intracranial hemorrhage. Based on current guidelines, there are three effective regimens:

1. Intramuscular (IM) administration (preferred):

   • 1 mg of vitamin K1 as a single dose at birth 1
   • Most reliable method with highest efficacy

2. Oral administration options (if IM is refused):

   • Option 1: 3 × 2 mg vitamin K1 orally at birth, at 4-6 days, and at 4-6 weeks 1
   • Option 2: 2 mg vitamin K1 orally at birth, followed by weekly doses of 1 mg for 3 months 1

Special Considerations

Preterm and High-Risk Infants

• Preterm and term infants up to 12 months of age on parenteral nutrition should receive 10 μg/kg/day of vitamin K 2, 3
• For infants at high risk of hemorrhage (premature, perinatal asphyxia, difficult delivery, delayed feeding, known liver disease), the first dose must be administered by IM or slow intravenous route 4

Maternal Medication Considerations

• Infants whose mothers took medications that interfere with vitamin K metabolism (anticoagulants, anticonvulsants, barbiturates) require special attention 3, 4
• For these infants, antenatal maternal prophylaxis (10-20 mg/day orally for 15-30 days before delivery) may be considered to prevent early VKDB 4

Monitoring and Follow-up

• The date, dose, and mode of administration should be documented for all infants 1
• Parental refusal should be documented due to the risk of late VKDB 1
• For oral administration, if the infant vomits or regurgitates within 1 hour, repeating the dose may be appropriate 1

Route Selection Considerations

The IM route is preferred for several reasons:

• Higher reliability of administration
• Better protection against late VKDB compared to single oral dose 1, 5
• Oral administration is not appropriate for:
  • Preterm infants
  • Newborns with cholestasis
  • Infants with impaired intestinal absorption
  • Infants too unwell to take oral vitamin K1 1

Potential Risks and Benefits

• VKDB is a potentially life-threatening condition that can cause severe bleeding, including intracranial hemorrhage 3
• Although concerns were raised in the past about potential links between IM vitamin K and childhood cancer, more recent evidence has largely ruled out this association 1, 4
• The benefits of vitamin K prophylaxis in preventing VKDB clearly outweigh any theoretical risks

Practical Implementation

• Parent education about the importance of vitamin K prophylaxis improves compliance 1
• For formula-fed infants without hemorrhage risk, 2 mg oral dose at birth followed by a second 2 mg oral dose between days 2-7 may be sufficient 4
• For exclusively breastfed infants, additional supplementation is required due to low vitamin K content in breast milk 3, 4

By following these evidence-based recommendations, clinicians can effectively prevent VKDB in newborns and minimize the risk of serious bleeding complications.