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Serum or plasma concentration of vitamin K-dependent coagulation factors (Factor VII, Factor X, Protein C, Protein S)

Published: August 9, 2026Updated: August 16, 2026

This test measures certain blood proteins that help your blood clot normally when injured. Low levels may indicate bleeding disorders or vitamin K deficiency.

Quick summary

["Assesses blood clotting function with key proteins affected by vitamin K."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
27816-8
Short code
vWF Ag Act/Nor PPP IA
Synonyms
vWF Ag Act/Nor PPP IA
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like easy bruising, excessive bleeding, or if you’re taking blood thinners like warfarin. It can also help diagnose conditions like vitamin K deficiency, liver disease, or inherited clotting disorders.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications (especially blood thinners) or recent surgeries. Fasted or non-fasted blood draws are typically acceptable.

How the Test Works

A blood sample is taken from a vein, usually in your arm. The lab analyzes the sample for specific proteins that require vitamin K to function properly.

Possible Results and Next Steps

Results may show low, normal, or high levels of these proteins. Abnormal results could prompt further testing (e.g., vitamin K levels, liver function tests) or adjustments to medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Vitamin K-dependent coagulation factors panel

Frequently asked questions

What causes abnormal results?
Abnormal results can stem from conditions like liver disease, vitamin K deficiency, certain medications (e.g., antibiotics, anti-seizure drugs), or inherited clotting disorders. Your doctor will discuss findings in detail.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on lab processing times. Your doctor will contact you once they’re ready.
Can I eat or drink before the test?
No strict fasting is required, but avoid heavy meals right before the draw to minimize discomfort. Hydration is fine unless your doctor advises otherwise.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy