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Vitamin K-dependent clotting factors (serum/plasma concentration)

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

This test measures levels of specific proteins in your blood that help your blood clot normally. These proteins depend on vitamin K for proper function.

Quick summary

["Your blood clotting ability may be affected if these levels are too high or too low."]

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

Key facts at a glance

LOINC
79701-9
Short code
VLCFA.C22:1n9 SerPl-sCnc
Synonyms
VLCFA.C22:1n9 SerPl-sCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 bleeding problems, a history of easy bruising, or if you’re taking medications that affect blood clotting. It can also help diagnose conditions like vitamin K deficiency or liver disease that might impact clotting factors.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if your blood is drawn early in the morning. Wear comfortable clothing and bring any medications you’re currently taking.

During the Test

A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but the process usually takes just a few minutes. You can sit or lie down while the blood is drawn.

After the Test

You can resume normal activities immediately. Apply gentle pressure to the site to stop any bleeding, and check for signs of infection (like redness or swelling) over the next few days.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Vitamin K Factors

Frequently asked questions

What Does This Test Measure?
This test checks the concentration of proteins (factors II, VII, IX, and X) that require vitamin K to work properly. These factors are essential for normal blood clotting.
How Long Will Results Take?
Results are typically available within 24–48 hours, depending on your lab’s processing time. Your doctor will discuss the findings with you during a follow-up visit.
Can I Eat or Drink Before the Test?
If fasting is required, avoid food and liquids (except water) for 8–12 hours before the blood draw. If no fasting is needed, you can eat and drink normally.
  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