Carboxylated Vitamin K-Dependent Coagulation Factors (Serum)

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms of vitamin K deficiency, such as easy bruising, excessive bleeding, or unexplained nosebleeds. It may also be used in patients with liver disease, malabsorption issues (like celiac disease or Crohn’s), or those on certain medications that affect vitamin K levels. Rarely, it could be part of a broader evaluation for bleeding disorders or to monitor treatment for conditions like vitamin K deficiency or liver dysfunction.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test, but always follow your provider’s instructions. Bring any medications or supplements you’re taking, as some (like blood thinners) can affect results.

What the Test Involves

A blood sample will be drawn from a vein in your arm by a healthcare professional. The sample is sent to a lab for analysis. The process typically takes a few minutes, and you may feel slight discomfort, but it’s usually over quickly.

What the Results Mean

Lower-than-expected levels of carboxylated factors may indicate vitamin K deficiency, liver disease, or malabsorption problems. Higher-than-expected levels are less common but could suggest certain medications or rare genetic conditions. Your provider will discuss results in the context of your overall health and symptoms.