Vitamin K1, Serum
Use
Vitamin K1, or phylloquinone, is essential for blood coagulation as it facilitates the gamma-carboxylation of glutamate residues in clotting factors such as prothrombin and factors VII, IX, and X. Deficiency in vitamin K1 can lead to impaired blood coagulation and risk problems like hemorrhagic disease in newborns and other bleeding disorders. This test assesses circulating vitamin K1 levels to identify deficiencies that may result from poor dietary intake, malabsorption disorders, or interference from certain medications such as coumarin anticoagulants.
Special Instructions
This test requires fasting for 12 hours before specimen collection. Infants should have specimens collected before their next feeding. Use the General Request form if not ordering electronically.
Limitations
Testing of nonfasting specimens can result in elevated serum vitamin K1 concentrations, potentially leading to inaccurate assessments of deficiency. The use of vitamin K1 supplementation may also influence test results. These factors should be considered when interpreting the test outcomes.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 9622-2
- 9622-2
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
2 mL
Minimum Volume
0.75 mL
Container
Amber vial
Collection Instructions
Within 2 hours of collection, centrifuge the specimen. For red top tubes, immediately aliquot serum into an amber vial (preferred). Serum may sit on whole blood cells for up to a maximum of two hours before aliquoting. For serum gel tubes, immediately aliquot serum into an amber vial (preferred). Serum may sit on gel at ambient temperature for a maximum of 24 hours or refrigerated for a maximum of 7 days before aliquoting.
Patient Preparation
Fasting: 12 hours, required; Infants should have specimen collected before next feeding
Causes for Rejection
Lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 30 days |
| Refrigerated | 30 days |
| Frozen | 30 days |