Vitamin K

Note: this site is for informational purposes only. To view test results or book a test, use the NHS app in England or contact your GP.

The vitamin K test is a blood test in which a sample is taken from a vein to measure vitamin K levels and assess its role in blood clotting. It is used to help detect vitamin K deficiency, which can lead to bleeding problems due to impaired clotting factor production.

What is being tested?

Increasingly when requesting the vitamin K level laboratories may offer protein induced by vitamin K absence or antagonist-II (PIVKA-II). This marker increases when the vitamin K is low or inhibited e.g. by warfarin. There are three different subtypes of vitamin K and PIVKA-II therefore provides a sensitive marker of tissue status of vitamin K activity/​concentration.

What else do I need to know?

Liver disease can increase PIVKA-II causing a false result.

Sample required?

A blood sample taken from a vein in the arm

Test preparation needed?

None