PrescriptionGiant is a FREE prescription savings program that can save you up to 75% on your prescriptions with or without insurance!

Vitamin K1 (Generic Phytonadione)

Actual product appearance may differ slightly.

Click the CARD below to print or take a screenshot on your mobile phone or tablet. There is no need to download another app!

If you would like to personalize your card enter your full name in the member name field below the card at this link and click the Update button.

Why is this medication prescribed?

Phytonadione, also known as vitamin K1, is a fat-soluble vitamin that plays a crucial role in blood clotting. It is often prescribed to treat or prevent bleeding disorders caused by a deficiency of vitamin K. Vitamin K is essential for the synthesis of clotting factors in the liver, and a deficiency can lead to impaired blood clotting, resulting in excessive bleeding.

Here are some common reasons why phytonadione may be prescribed:

  • Warfarin Therapy: Phytonadione is often used in individuals who are taking anticoagulant medications like warfarin. Warfarin works by inhibiting the action of vitamin K, and supplementing with phytonadione can help regulate the blood clotting process.
  • Vitamin K Deficiency: Phytonadione may be prescribed in cases of vitamin K deficiency, which can occur due to conditions that interfere with the absorption of fat or the synthesis of vitamin K in the body.
  • Newborns: Newborns are often given a single dose of phytonadione shortly after birth to prevent a rare bleeding disorder called vitamin K deficiency bleeding (VKDB).

The dosage and administration of phytonadione will vary depending on the specific medical condition and the healthcare provider’s recommendations. It is typically administered orally or as an injection. The healthcare provider will determine the appropriate dosage based on the individual’s needs.

How should this medicine be used?

The use of phytonadione (vitamin K1) should always be under the guidance and prescription of a healthcare professional. The specific dosage and administration instructions can vary based on the individual’s medical condition and needs. Here are some general guidelines:

  • Route of Administration: Phytonadione can be administered orally or through injection, depending on the severity of the condition and the healthcare provider’s recommendation.
  • Oral Administration: If prescribed in oral form, phytonadione is usually taken with or without food. Follow the healthcare provider’s instructions regarding the timing and frequency of oral doses.
  • Injection Administration: If given by injection, a healthcare professional will administer the medication. In some cases, it may be given as an intramuscular injection (into the muscle) or as a subcutaneous injection (under the skin).
  • Dosage: The dosage of phytonadione will be determined by the healthcare provider based on the specific medical condition, the severity of the deficiency or bleeding disorder, and other individual factors. It’s important to adhere to the prescribed dosage and not self-adjust without consulting a healthcare professional.
  • Monitoring: Regular monitoring of blood clotting factors may be necessary during treatment, especially for individuals on anticoagulant therapy like warfarin. This helps ensure that the dosage of phytonadione is appropriate and effective in managing blood clotting.
  • Follow-Up: Attend follow-up appointments as scheduled by the healthcare provider to assess the effectiveness of the treatment and make any necessary adjustments.

It is crucial to inform your healthcare provider about any other medications, supplements, or medical conditions you have before starting phytonadione, as interactions or contraindications may exist.

Always follow the instructions provided by your healthcare provider and seek their guidance if you have any questions or concerns about the use of phytonadione. Do not self-prescribe or change the dosage without proper medical supervision.

Other uses for this medicine

While phytonadione (vitamin K1) is primarily used to treat or prevent bleeding disorders associated with vitamin K deficiency, there are some other potential uses for this vitamin:

  • Bone Health: Vitamin K is also involved in bone metabolism, and some studies suggest that it may play a role in maintaining bone density and preventing osteoporosis. However, the evidence in this area is not as strong as it is for its role in blood clotting.
  • Cardiovascular Health: There is ongoing research exploring the potential role of vitamin K in cardiovascular health, particularly its involvement in preventing arterial calcification. However, more research is needed to establish clear guidelines in this regard.

What special precautions should I follow?

As for special precautions, here are some important considerations:

  • Medical History: Before taking phytonadione, inform your healthcare provider about your complete medical history, including any existing health conditions and medications you are taking. This is crucial to ensure that there are no contraindications or interactions.
  • Pregnancy and Breastfeeding: Pregnant or breastfeeding individuals should use phytonadione only under the guidance of a healthcare professional. The potential benefits and risks should be carefully considered.
  • Interactions with Medications: Vitamin K can interact with certain medications, particularly anticoagulants like warfarin. The dosage of phytonadione may need to be adjusted in such cases, and close monitoring is essential.
  • Allergies: If you are allergic to phytonadione or any of its components, you should not use it. Always check with your healthcare provider if you have known allergies.
  • Dosage Adjustment: Do not alter the dosage of phytonadione without consulting your healthcare provider. Changing the dosage without proper guidance can have implications for blood clotting and overall health.
  • Monitoring: Regular monitoring of blood clotting factors may be necessary, especially if you are on anticoagulant therapy. This helps ensure that the dosage of phytonadione is appropriate for your individual needs.

Always follow your healthcare provider’s instructions, and consult them if you have any concerns or questions about phytonadione or its use in your specific situation.

What special dietary instructions should I follow?

Special Dietary Instructions for phytonadione:

  • Consistent Vitamin K Intake: Maintain a consistent intake of foods rich in vitamin K. Sudden changes in vitamin K intake can affect the effectiveness of medications like warfarin.
  • Green Leafy Vegetables: If you are taking anticoagulant medications, be mindful of your consumption of green leafy vegetables, as they are rich in vitamin K. Consistency in your diet can help maintain stable blood clotting.

What should I do if I forget a dose?

If you forget to take a dose of phytonadione, follow these general guidelines:

  • Oral Medication: Take the missed dose as soon as you remember, unless it is almost time for your next scheduled dose. In that case, skip the missed dose and continue with your regular dosing schedule.
  • Injection: If you miss an injection, contact your healthcare provider for guidance. It may be necessary to reschedule the injection.

What side effects can this medication cause?

Phytonadione (vitamin K1) is generally considered safe when used as directed under the supervision of a healthcare professional. However, like any medication, it may cause side effects in some individuals. Common side effects are typically mild and may include:

  • Pain or swelling at the injection site: This is more relevant if phytonadione is administered by injection.
  • Redness or irritation at the injection site: Again, this is more common with injectable forms of phytonadione.
  • Unpleasant taste: If taking phytonadione orally, some people may experience an unpleasant taste.

Serious side effects are rare, but they can occur. If you experience any of the following, seek medical attention promptly:

  • Allergic reactions: Symptoms may include rash, itching, swelling, severe dizziness, or difficulty breathing. An allergic reaction is a medical emergency.
  • Signs of a blood clot: Although rare, excessive vitamin K supplementation could theoretically increase the risk of blood clots. Seek medical attention if you experience symptoms such as sudden pain, swelling, warmth, or redness in the leg or arm.

It’s important to note that vitamin K can interact with certain medications, especially anticoagulants like warfarin. If you are on such medications, your healthcare provider will carefully monitor your blood clotting levels and adjust your dosage accordingly.

As everyone’s response to medication can vary, if you experience any unexpected or severe side effects while taking phytonadione, contact your healthcare provider promptly.

This information is not exhaustive, and individual responses to medications can vary. Always consult with your healthcare provider for personalized advice and information about the specific risks and benefits of phytonadione in your particular situation.

What should I know about storage and disposal of this medication?


  • Follow Instructions: Store phytonadione as directed by your healthcare provider or as indicated on the prescription label. Different formulations (oral, injectable) may have specific storage requirements.
  • Room Temperature: In general, phytonadione is typically stored at room temperature, away from moisture and heat. However, follow the specific storage instructions provided.
  • Keep Out of Reach of Children: Ensure that the medication is stored in a location where children cannot access it.


  • Dispose Properly: Follow your local guidelines for the disposal of medications. Do not flush medications down the toilet unless specifically instructed to do so.
  • Medication Take-Back Programs: Check if there are medication take-back programs in your community or follow any specific disposal instructions provided by your healthcare provider or pharmacist.

In case of emergency/overdose

  • Contact Emergency Services: In case of an emergency or suspected overdose, call your local emergency number (e.g., 911 in the United States) immediately.
  • Poison Control Center: You can also contact your local poison control center for guidance. In the United States, the Poison Help hotline is 1-800-222-1222.
  • Symptoms of Overdose: Symptoms of an overdose may include unusual bleeding or bruising, blood in the urine or stool, and other signs of excessive vitamin K.

What other information should I know?

  • Regular Monitoring: If you are taking phytonadione as part of a treatment plan, your healthcare provider may conduct regular blood tests to monitor your clotting factors and adjust the dosage as needed.
  • Inform Healthcare Providers: Always inform other healthcare providers, including dentists and surgeons, about your use of phytonadione. This is important, especially if you are undergoing any medical procedures.
  • Follow Healthcare Provider’s Advice: Adhere to your healthcare provider’s instructions regarding dosage, diet, and other recommendations. If you have any questions or concerns, discuss them with your healthcare provider.
  • Keep Appointments: Attend follow-up appointments as scheduled by your healthcare provider to ensure the effectiveness of the treatment.
  • Consistent Diet: If you are on anticoagulant therapy, maintain a consistent intake of vitamin K in your diet. Sudden changes in vitamin K intake can affect the effectiveness of medications like warfarin.

Always consult with your healthcare provider or pharmacist if you have specific questions about the storage, disposal, or any other aspects of your medication. This information is general and may not cover all individual circumstances.

Copyright © 2023