Vitamin K Blood Test: Normal Range and Interpretation

Vitamin K is a fat-soluble vitamin essential for blood clotting and bone health. The Vitamin K normal range is typically 0.2–3.2 ng/mL in blood. Low Vitamin K levels increase bleeding risk, while high levels usually reflect dietary intake or supplementation. This test helps evaluate clotting function and detect deficiency.

Contents

Result interpretation Vitamin K

What your result means based on common reference ranges

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Normal

Vitamin K levels within 0.2–3.2 ng/mL indicate proper coagulation and normal bone metabolism function.

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Mildly elevated

Mildly elevated Vitamin K levels often reflect increased dietary intake without clinical impact on coagulation balance.

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Significantly elevated

Significantly high Vitamin K levels may result from excessive supplementation and can interfere with anticoagulant therapy effects.

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Below normal

Low Vitamin K levels impair clotting factor synthesis, increasing bleeding risk and indicating possible malabsorption or liver dysfunction.

🔬 Check your value Vitamin K

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What is Vitamin K?

Vitamin K plays a central role in activating proteins required for blood coagulation and calcium binding in bone tissue. A Vitamin K blood test measures phylloquinone (K1) levels, reflecting dietary intake and absorption efficiency. It is clinically relevant in cases of bleeding disorders, liver dysfunction, or malabsorption syndromes. Low levels impair clotting factor synthesis, increasing bleeding risk, while normal levels support hemostasis and bone metabolism. The test is often interpreted alongside PT/INR to assess coagulation status and identify deficiencies or medication effects.

Reference ranges

Group Normal range Unit
Men 0.2 – 3.2 ng/mL
Women 0.2 – 3.2 ng/mL
Children 0.2 – 3.2 ng/mL

Causes of abnormal values

Causes of low Vitamin K

  • • Malabsorption syndromes — impaired fat absorption reduces Vitamin K uptake
  • • Long-term antibiotic use — disruption of gut microbiota decreases endogenous Vitamin K production
  • • Biliary obstruction — lack of bile prevents proper fat-soluble vitamin absorption
  • • Poor dietary intake — insufficient consumption of green vegetables leads to deficiency

Causes of high Vitamin K

  • • Excessive supplementation — high-dose Vitamin K intake exceeds physiological needs and accumulates in circulation
  • • High leafy green intake — frequent consumption of kale or spinach increases Vitamin K levels
  • • Vitamin K injections — recent therapeutic administration temporarily elevates blood concentration
  • • High-fat diet — enhanced fat absorption increases uptake of fat-soluble vitamins
  • • Liver dysfunction — impaired processing leads to accumulation in bloodstream
  • • Multivitamin overuse — combined sources contribute to elevated Vitamin K levels

Vitamin K in combination with other markers

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Low Vitamin K + High PT/INR Prolonged clotting time due to deficiency affecting coagulation cascade and hemostasis function.
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Low Vitamin K + Low Bone Density Impaired calcium binding increases fracture risk and weakens skeletal structure.
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Normal Vitamin K + High PT/INR Suggests liver disease or anticoagulant medication effect rather than vitamin deficiency.
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Low Vitamin K + Malabsorption markers Indicates intestinal absorption disorder affecting fat-soluble vitamins and nutrient status.

Possible symptoms

  • •Easy bruising
  • •Frequent nosebleeds
  • •Bleeding gums
  • •Heavy menstrual bleeding
  • •Prolonged bleeding from cuts

When to see a doctor

Consult a doctor if Vitamin K levels fall below 0.2 ng/mL or if unexplained bleeding occurs. Seek medical advice if bruising appears without injury or if clotting abnormalities persist. Persistent abnormal results or symptoms require evaluation of liver function or nutrient absorption.

What to do if abnormal

  • 🥬 Increase intake of leafy greens consistently
  • ⚖️ Maintain stable diet if using anticoagulants
  • 🧠 Address gut health and absorption issues
  • 💊 Review supplements and avoid unnecessary high doses
  • 🩺 Monitor levels with follow-up blood tests

The information on this page is intended for general understanding of test results and does not replace medical consultation. Accurate interpretation requires considering other blood markers and individual factors.

Content is based on medical literature and used within the PulseBook analytical system.

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Frequently asked questions

What is the Vitamin K normal range?

The Vitamin K normal range is typically 0.2–3.2 ng/mL. This level ensures proper blood clotting and supports bone health. Values outside this range may indicate dietary imbalance, malabsorption, or medication effects, and should be interpreted alongside clinical context.

What does a Vitamin K blood test measure?

A Vitamin K blood test measures the level of phylloquinone (Vitamin K1) in circulation. It helps assess clotting function and detect deficiencies that may lead to bleeding disorders or impaired bone metabolism.

What are low Vitamin K levels?

Low Vitamin K levels indicate insufficient availability for clotting factor activation. This increases bleeding risk and may result from malabsorption, poor diet, or prolonged antibiotic use affecting gut bacteria.

What causes low Vitamin K levels?

Low Vitamin K levels are commonly caused by malabsorption syndromes, bile duct obstruction, poor diet, or long-term antibiotic use. These conditions reduce absorption or production of Vitamin K, leading to deficiency.

What is the Vitamin K blood test name?

The Vitamin K blood test is often listed as a "Phylloquinone test" or "Vitamin K1 serum test." These names refer specifically to the measurement of Vitamin K1 in the bloodstream.

How does Vitamin K anticoagulant interaction work?

Vitamin K directly affects how anticoagulant medications like warfarin function. Sudden changes in Vitamin K intake can alter drug effectiveness, either increasing bleeding risk or reducing anticoagulant control.

What do high Vitamin K levels mean?

High Vitamin K levels usually reflect increased dietary intake or supplementation. In most cases, this is not harmful but may interfere with anticoagulant therapy and should be monitored if medication is used.