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24-Hour Vitamin K Intake Measurement

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

This test measures how much vitamin K you consumed over the past 24 hours. Vitamin K is important for blood clotting and bone health.

Quick summary

["Understanding your vitamin K intake helps assess dietary habits and potential deficiencies or excesses."]

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

Key facts at a glance

LOINC
81079-6
Short code
Vit K intake 24h Measured
Synonyms
Vit K intake 24h Measured
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
20
Ref high
400
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
measured
CPT
82670
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 Is This Test Done?

Your healthcare provider may order this test if you have concerns about vitamin K intake, such as dietary restrictions, malabsorption issues, or if you’re taking medications that affect vitamin K levels. It can also help monitor long-term dietary patterns or evaluate nutritional status.

What Does This Test Involve?

You’ll be asked to record all vitamin K-containing foods and supplements consumed in the past 24 hours. No blood or urine sample is taken—this is a dietary assessment rather than a lab measurement.

How Is the Test Performed?

You’ll typically receive a dietary log or questionnaire to track foods like leafy greens, nuts, and some oils, which contain vitamin K. Some providers may use a food frequency questionnaire to estimate intake.

What Are Common Reasons for This Test?

Common reasons include evaluating dietary compliance in patients with liver disease, bile duct obstruction, or those on certain medications (e.g., warfarin) that interact with vitamin K. It may also help identify dietary gaps in patients with nutritional deficiencies.

Reference range

Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance:

Short name

Vitamin K Intake (24h)

Frequently asked questions

How accurate is this test?
This test is based on self-reported dietary intake, which can be influenced by memory, portion size estimation, or changes in eating habits. It’s not a direct blood or biochemical measurement but provides a snapshot of dietary patterns over 24 hours.
Can this test detect vitamin K deficiency?
No, this test does not measure vitamin K levels in your body. Instead, it assesses your intake. A blood test (e.g., prothrombin time or vitamin K levels) would be needed to evaluate deficiency.
Does this test require fasting?
No, fasting is not required for this test. You can eat and drink normally while recording your vitamin K intake.
  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