What is the recommended dose of vitamin K (phytonadione) for a 4-year-old child?

Vitamin K Dosing for a 4-Year-Old Child

For a 4-year-old child, the recommended dose of vitamin K (phytonadione) is 200 μg/day (micrograms per day). 1

Evidence-Based Dosing Recommendations

The most recent and authoritative guidelines on vitamin K dosing for children come from the ESPGHAN/ESPEN/ESPR/CSPEN guidelines on pediatric parenteral nutrition, which provide specific age-based recommendations:

• For preterm and term infants up to 12 months: 10 μg/kg/day
• For children older than 12 months (including 4-year-olds): 200 μg/day 1

For children with specific conditions such as cystic fibrosis, the dosing may be higher:

• Children 1-10 years old with cystic fibrosis: 1-10 mg/day of vitamin K1 1

Administration Routes

Vitamin K can be administered through different routes depending on the clinical situation:

• Oral administration: Preferred for routine supplementation in children without bleeding risk
• Intramuscular injection: More effective for prevention of late vitamin K deficiency bleeding
• Intravenous administration: Reserved for emergency situations with active bleeding or severe deficiency 2

Clinical Considerations

Indications for Vitamin K Supplementation

Vitamin K supplementation is particularly important in:

• Children with fat malabsorption conditions
• Those on long-term antibiotic therapy
• Children with liver disease
• Those with malnutrition 1

Monitoring

• Classical coagulation tests can be used for indirect evaluation of vitamin K status, but they are not specific to vitamin K deficiency 1
• Undercarboxylated Serum Vitamin K-Dependent Proteins (PIVKA-II) are more useful biomarkers of subclinical vitamin K deficiency 1

Safety Considerations

• Vitamin K1 (phytonadione/phylloquinone) is considered the safest form of supplementation 1
• While rare, anaphylactoid reactions can occur with intravenous administration of vitamin K 3
• There are no known adverse effects associated with oral vitamin K1 supplementation at recommended doses 1

Special Situations

For children with chronic cholestasis or severe bleeding:

• Higher doses may be required
• Intravenous administration may be necessary in emergency situations 4

For children at high risk of vitamin K deficiency (e.g., those with cystic fibrosis, liver disease, or on long-term antibiotics):

• More frequent monitoring may be needed
• Higher supplementation doses (1-10 mg/day) may be appropriate 1

Daily administration is preferred over weekly dosing due to the low storage capacity of vitamin K in the body 1.