Assessing circulating vitamin K1 concentration
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Phylloquinone
Phytonadione
Mephyton
Phytomenadione
Synthex
Konakion
Serum
Patient Preparation: Fasting overnight (12-14 hours) (infants-collect prior to next feeding).
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions: Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.
If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.
0.75 mL
Gross hemolysis | OK |
Gross lipemia | Reject |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 30 days | |
Ambient | 30 days | ||
Frozen | 30 days |
Assessing circulating vitamin K1 concentration
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 proteins S and 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.
<18 years: Not established
> or =18 years: 0.10-2.20 ng/mL
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.
1. Office of Dietary Supplements: Vitamin K Fact Sheet for Health Professionals. National Institutes of Health; Updated March 29, 2021. Accessed April 23, 2024. Available at https://ods.od.nih.gov/factsheets/vitaminK-HealthProfessional/
2. Lippi G, Franchini M. Vitamin K in neonates: Facts and myths. Blood Transfus. 2011;9(1):4-9. doi:10.2450/2010.0034-10
3. Greer FR. Vitamin K the basics-What's new? Early Hum Dev. 2010;86 Suppl 1:43-7. doi:10.1016/j.earlhumdev.2010.01.015
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 with analysis on a tandem mass spectrometer equipped with a heated nebulizer ion source using multiple-reaction monitoring.(Unpublished Mayo method)
Monday through Friday
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
84597
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
VITK1 | Vitamin K1, S | 9622-2 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
62167 | Vitamin K1, S | 9622-2 |