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

Maximum Vitamin K (Phylloquinone) Dose for a 4-Year-Old Child

For a 4-year-old child, the maximum safe dose of vitamin K (phylloquinone) is 10 mg/day. 1

Dosing Guidelines by Age

Vitamin K (phylloquinone) dosing varies by age:

• Infants (0-12 months): 0.3-1 mg/day or 10 μg/kg/day if on parenteral nutrition 1
• Children (1-10 years): 1-10 mg/day depending on age and risk factors 1
• Children (≥11 years and adults): Up to 10 mg/day 1

Safety Profile of Vitamin K

Vitamin K1 (phylloquinone) is considered to have an excellent safety profile:

• No known adverse effects of supplementation have been reported 1
• Vitamin K toxicity (phylloquinone) is not a concern at recommended doses 1
• Even doses that are 10-20 times the Recommended Dietary Allowance (RDA) for adults have shown no adverse effects 2

Special Considerations

Risk Factors Requiring Higher Dosing

Higher doses within the 1-10 mg/day range may be considered for children with:

• Long-term antibiotic use 1
• Liver disease 1
• Severe malabsorption 1
• Cystic fibrosis 1

Administration Recommendations

• Daily administration is preferred due to the low storage capacity of vitamin K 1
• Phylloquinone (vitamin K1) is the recommended form of supplementation, preferred over menadione salts 1

Monitoring

There are no routinely used biochemical indicators of vitamin K status in standard clinical practice. When necessary, vitamin K status can be evaluated by:

• Measuring serum concentrations of vitamin K
• Measuring PIVKA-II (protein induced by vitamin K absence)
• Measuring undercarboxylated osteocalcin
• Prothrombin time (insensitive, only becomes elevated in severe deficiency) 1

Clinical Implications

Vitamin K plays crucial roles in:

• Blood clotting (regulates coagulation factors II, VII, IX, X, protein C, and protein S) 1
• Bone health (synthesis of osteocalcin) 1

Deficiency can result in clinically significant bleeding and may contribute to low bone mineral density 1.

While the maximum dose is 10 mg/day for a 4-year-old, the actual required dose should be determined based on the child's specific clinical situation, with special attention to risk factors for vitamin K deficiency.