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Test Code VITK1 Vitamin K1, Serum

Useful For

Assessment of circulating vitamin K1 concentration

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Vitamin K1, S

Specimen Type


Specimen Required

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 2 mL

Collection Instructions: Fasting overnight (12-14 hours) (infants-draw prior to next feeding).

Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 30 days
  Ambient  30 days
  Frozen  30 days

Reject Due To


Mild OK; Gross OK


Mild reject; Gross reject


Mild OK; Gross OK



Clinical Information

Vitamin K1 or phylloquinone is part of a group of similar fat soluble vitamins in which the 2-methyl-1,4-naphthoquinone ring is common. Phylloquinone is found in high amounts in leafy green vegetables and some fruits (avocado, kiwi). It is a required cofactor involved in the gamma-carboxylation of glutamate residues of several proteins. Most notably, the inactive forms of the coagulation factors prothrombin (factor II), factors VII, IX, and X and protein S and protein C are converted to their active forms by the transformation of glutamate residues to gamma-carboxyglutamic acid (Gla). Other proteins such as those involved in bone metabolism, cell growth, and apoptosis also undergo this Gla transformation. Measurement of vitamin K1 (phylloquinone) in fasting serum is a strong indicator of dietary intake and status.

Reference Values

≥18 years: 0.10-2.20 ng/mL

<18 years: not established


Low vitamin K1 concentrations in the serum are indicative of insufficiency and poor vitamin K1 status.


Testing of nonfasting specimens or the use of vitamin K1 supplementation can result in elevated serum vitamin K1 concentrations.

Clinical Reference

1. Vermeer C: Vitamin K: the effect on health beyond coagulation-an overview. Food Nutr Res 2012;56:5329

2. Lippi G, Franchini M: Vitamin K in neonates: facts and myths. Blood Transfus 2011;9:4-9

3. Greer FR: Vitamin K the basics-What's new? Early Hum Dev 2010;86:S43-S47

Method Description

Deuterated stable isotope (vitamin K1-d7) is added to a serum sample as an internal standard. Protein is precipitated from the mixture by the addition of ethanol. Vitamin K1 and internal standard are extracted from the resulting supernatant by solid-phase extraction. Vitamin K1 and internal standard are then separated utilizing high-throughput liquid chromatography (HTLC) with analysis on a tandem mass spectrometer equipped with a heated nebulizer ion source using multiple-reaction monitoring.(Unpublished Mayo method)

Day(s) and Time(s) Performed

Monday through Friday; 4 p.m.

Analytic Time

2 days

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
VITK1 Vitamin K1, S 9622-2


Result ID Test Result Name Result LOINC Value
62167 Vitamin K1, S 9622-2

NY State Approved