What is the indication of vitamin K tablet?

October 10, 2025 •

3 min read

According to the National Institutes of Health, clinically significant vitamin K deficiency in adults is very rare. However, when issues like bleeding disorders or medication interference arise, understanding what is the indication of vitamin K tablet becomes essential for proper medical management and treatment.

Quick Summary

Vitamin K tablets are used to address blood clotting problems arising from vitamin K deficiency, adverse drug effects, or malabsorption issues. They are also prescribed to reverse the effect of certain oral anticoagulants, like warfarin, in non-emergency scenarios.

Key Points

Warfarin Over-anticoagulation: Low-dose oral vitamin K is a standard treatment for reducing an excessively high INR (blood thinning) in patients on warfarin who are not experiencing significant bleeding.
Vitamin K Deficiency: Tablets are used to treat deficiencies caused by conditions that impair fat-soluble vitamin absorption, such as obstructive jaundice, celiac disease, and cystic fibrosis.
Drug Interference: Oral vitamin K can correct hypoprothrombinemia induced by certain antibiotics and high-dose salicylates that interfere with vitamin K metabolism.
No Immediate Effect: Oral tablets work slowly (6-10 hours) and are unsuitable for emergency bleeding, which requires faster intervention like IV vitamin K or blood products.
Prescription Only: High-dose vitamin K tablets are a prescription medication and should only be used under a healthcare provider's guidance to avoid complications.
Not for Neonatal Prophylaxis: Intramuscular injection is the recommended and most effective method for preventing vitamin K deficiency bleeding (VKDB) in newborns, not oral tablets.
Liver Disease Limitation: In severe liver disease, vitamin K may not be effective at correcting coagulopathy because the liver's ability to produce clotting factors is inherently impaired.

Vitamin K is a vital fat-soluble vitamin necessary for the body's natural blood clotting processes. While most healthy adults obtain sufficient amounts through diet and gut bacteria, certain medical conditions or medications can disrupt this balance, leading to a deficiency. When this occurs, prescription vitamin K tablets, containing phytonadione (vitamin K1), are used to correct the problem.

The Primary Indications for Vitamin K Tablets

The main uses for oral vitamin K are centered on managing coagulopathy, a condition where the blood's ability to clot is impaired. The specific indications include:

1. Reversing the Effects of Warfarin

Warfarin is an anticoagulant that works by blocking vitamin K's action, preventing the synthesis of clotting factors. Oral vitamin K is used for gradual reversal of high INR in non-bleeding patients, avoiding risks associated with rapid correction.

2. Treating Hypoprothrombinemia Due to Malabsorption

Conditions interfering with fat-soluble vitamin absorption, such as obstructive jaundice (requiring concurrent bile salts), cystic fibrosis, celiac disease, and intestinal resection, can cause vitamin K deficiency and bleeding. Oral vitamin K treats this deficiency.

3. Managing Drug-Induced Deficiency

Certain medications, like some antibiotics that affect gut bacteria or high-dose salicylates, can disrupt vitamin K metabolism. Oral vitamin K is indicated for hypoprothrombinemia caused by these drug interactions.

4. Supporting Coagulation in Liver Disease

Liver disease can impair clotting factor production. While oral vitamin K may be used, its effectiveness is debated and depends on the liver damage severity. In severe cases, the liver might not respond, and other treatments like fresh frozen plasma may be needed. A vitamin K trial can help differentiate deficiency from liver dysfunction.

Oral vs. Other Routes of Administration

The route of vitamin K administration depends on the situation's urgency and severity.


Feature	Oral Vitamin K Tablets	Intravenous (IV) Vitamin K	Intramuscular (IM)/Subcutaneous (SC) Vitamin K
Onset of Action	6 to 10 hours for effect, peaking around 24 hours.	Rapid, 1 to 2 hours for onset.	Slower and more unpredictable absorption compared to oral or IV routes.
Primary Use Case	Non-emergency situations, asymptomatic high INR, and long-term malabsorption issues.	Severe, active bleeding or urgent situations requiring rapid reversal.	Used for prophylaxis in newborns, but not recommended for adults due to inconsistent absorption and risk of hematoma.
Risks/Considerations	Absorption depends on bile salts. Less risk of acute adverse reaction.	Higher risk of anaphylactic or hypersensitivity reactions; requires close monitoring and slow infusion.	Risk of bleeding at injection site, especially with elevated INR.
Monitoring	Requires regular INR checks to ensure correct dosage.	Continuous monitoring during and after administration.	Less precise monitoring due to unpredictable absorption.

Important Precautions and Considerations

Taking oral vitamin K requires medical supervision. Key considerations include:

Oral vitamin K is a prescription medication.
Patients on warfarin need consistent dietary vitamin K intake.
Excessive use for warfarin reversal can lead to resistance.
Vitamin K only reverses vitamin K antagonist anticoagulants like warfarin, not others like heparin or DOACs.
Onset is slow (6-10 hours), making it unsuitable for emergency bleeding.

Conclusion

Ultimately, what is the indication of vitamin K tablet? It is a vital tool for specific blood clotting disorders, particularly severe deficiencies from malabsorption, medication interference, or non-urgent warfarin reversal. It is not for healthy individuals and requires medical supervision and monitoring due to its impact on coagulation.

For more detailed information on phytonadione, consult the MedlinePlus drug information page at the National Library of Medicine: Phytonadione: MedlinePlus Drug Information.

Frequently Asked Questions

High-dose vitamin K (phytonadione) tablets are prescription-only and used for specific medical conditions. Lower-dose vitamin K is available in some dietary supplements, but you should not self-medicate for bleeding issues without a doctor's guidance.

Symptoms of a severe deficiency can include unusual bruising, bleeding from the nose or wounds, blood in urine or stool, and black, tarry stools. In newborns, it can cause life-threatening internal bleeding.

Oral vitamin K tablets typically start to exert their effect on blood clotting within 6 to 10 hours, with a maximum effect often seen around 24 hours after administration. The precise timing can vary depending on the individual.

Intramuscular injection of vitamin K is the recommended and most effective prophylactic treatment for newborns to prevent vitamin K deficiency bleeding (VKDB). The oral route has absorption and compliance issues that make it less reliable for this purpose.

No, vitamin K is only effective for reversing the effects of vitamin K antagonist anticoagulants like warfarin. It will not reverse the effects of other types of blood thinners, such as heparin or direct oral anticoagulants (DOACs).

While a balanced diet is important, severe vitamin K deficiency, particularly from malabsorption or drug interference, cannot be corrected by diet alone. Prescription tablets are necessary to restore normal clotting function.

Bile salts are necessary for the intestinal absorption of fat-soluble vitamins like K. In conditions like obstructive jaundice where bile flow is blocked, oral vitamin K must be administered alongside bile salts for proper absorption.

No, vitamin K tablets do not treat liver disease itself. In severe liver disease, where the liver is damaged and cannot produce clotting factors, vitamin K supplementation may have limited effect. The underlying liver condition remains the primary issue.