When should vitamin K be administered?

Vitamin K Administration Guidelines

Vitamin K should be administered to all newborns at birth, with intramuscular injection being the preferred route (1 mg vitamin K1), though oral regimens are acceptable alternatives in specific situations. 1, 2

Newborns and Infants

Healthy Term Newborns

• Intramuscular (IM) route (preferred): 1 mg vitamin K1 as a single dose at birth 1, 2
• Oral route alternatives (if IM not possible or refused):
  • Option 1: 3 × 2 mg vitamin K1 orally at birth, at 4-6 days, and at 4-6 weeks
  • Option 2: 2 mg vitamin K1 orally at birth, followed by weekly doses of 1 mg for 3 months 2

High-Risk Newborns

For infants with increased bleeding risk (premature, perinatal asphyxia, difficult delivery, delayed feeding, liver disease):

• First dose must be administered via IM or slow IV route 3, 4
• Subsequent doses should be individualized based on clinical status 4

Preterm and Term Infants on Parenteral Nutrition

• 10 μg/kg/day of vitamin K for infants up to 12 months of age 1
• Older children: 200 μg/day 1

Special Situations

Exclusively Breastfed Infants

• Higher risk of vitamin K deficiency due to low concentrations in breast milk 3, 4
• After initial prophylaxis, weekly oral administration of 2 mg (or 25 μg/day) vitamin K until completion of breastfeeding 4

Infants of Mothers on Medications Affecting Vitamin K

For mothers taking anticoagulants, anticonvulsants, or barbiturates:

• Antenatal maternal prophylaxis: 10-20 mg/day orally for 15-30 days before delivery to prevent early VKDB 4
• Newborns require special supplementation protocol according to local policy 1

Vitamin K for Warfarin Reversal

Non-Urgent Reversal (INR 5-9, No Significant Bleeding)

• Omit next 1-2 doses of warfarin and give vitamin K1 1-2.5 mg orally 1
• INR should fall within 24 hours 1

Urgent Reversal (INR >9, No Significant Bleeding)

• Vitamin K1 3-5 mg orally 1
• Monitor INR closely and repeat vitamin K as necessary 1

Emergency Reversal (Serious Bleeding or Major Overdose)

• Vitamin K1 10 mg by slow IV infusion (over 30 minutes) 1, 5
• Supplement with fresh plasma or prothrombin complex concentrate 1, 5
• Additional doses of vitamin K1 may be needed every 12 hours 1

Monitoring

• Classical coagulation tests can be used in low-risk infants for indirect evaluation of vitamin K status 1
• Undercarboxylated Serum Vitamin K-Dependent Proteins (PIVKA-II) are useful biomarkers for subclinical deficiency in at-risk groups 1, 3

Important Considerations

• Document date, dose, and mode of administration for all vitamin K prophylaxis 2
• Record parental refusal after adequate information is provided due to risk of late VKDB 2
• If an infant vomits within 1 hour of oral administration, repeat the dose 2
• The oral route is not appropriate for preterm infants, those with cholestasis, impaired intestinal absorption, or those too unwell to take oral vitamin K1 2

Cautions

• A single dose of 0.2 mg IM vitamin K has been reported as insufficient to prevent late VKDB in exclusively breastfed infants 6
• Vitamin K1 administered IV can rarely cause anaphylactoid reactions with bronchospasm and cardiac arrest 1
• Rapid reversal of warfarin with vitamin K may return patients to a prothrombotic state 5

The evidence strongly supports universal vitamin K prophylaxis for all newborns, with the intramuscular route being most reliable for preventing the potentially fatal vitamin K deficiency bleeding.