Vitamin K Supplementation Guidelines
Introduction to Vitamin K
- Vitamin K supplementation is crucial for individuals with certain medical conditions, including cystic fibrosis, liver disease, and malabsorption, as recommended by the American Academy of Pediatrics and other guideline societies 1, 2
- The maximum safe upper limit for vitamin K2 has not been established, but levels below 100 ng/mL in blood are considered prudent, according to the American Autoimmune Related Diseases Association 3
Recommended Dosages
- The recommended dosage of vitamin K1 supplementation ranges from 0.3-1 mg/day for infants to 1-10 mg/day for children and adults, with daily administration preferred due to low storage capacity 1
Age-based dosages are suggested by the ESPGHAN/ESPEN/ESPR/CSPEN guidelines:
Age Group Recommended Dosage Preterm and term infants up to 12 months 10 μg/kg/day Children older than 12 months 200 μg/day Children with cystic fibrosis may require higher dosages, ranging from 0.3-1 mg/day for infants to 1-10 mg/day for children 1-10 years old 1
Special Populations
- Patients with liver disease, prolonged antibiotic use, or severe malabsorption may require higher doses of vitamin K1 supplementation, as stated by 1, 2
- Certain populations, including children with fat malabsorption conditions, those on long-term antibiotic therapy, children with liver disease, and those with malnutrition, are at high risk of vitamin K deficiency and may require more frequent monitoring and higher supplementation doses (1-10 mg/day) 1, 2
Safety and Monitoring
- Vitamin K1 (phylloquinone) is considered the safest form of supplementation, with no known adverse effects associated with oral administration at recommended doses, according to 1
- Classical coagulation tests can be used for indirect evaluation of vitamin K status but are not specific to vitamin K deficiency, while Undercarboxylated Serum Vitamin K-Dependent Proteins (PIVKA-II) are more useful biomarkers of subclinical vitamin K deficiency, as noted in 4