Vitamin K

Medication Information Leaflet

What is this medication for?

Vitamin K is used to treat or prevent Vitamin K deficiency. Vitamin K is needed for normal clotting of blood and a deficiency in Vitamin K can increase the risk of bleeding in the body.

Babies at birth have a small store of Vitamin K in their bodies, which is quickly used up in the first few days of life. A Vitamin K supplement may be given to prevent ‘Vitamin K Deficiency Bleeding (VKDB)’. VKDB can cause blood loss from the umbilical cord site, nose, mouth or brain of the baby.

Vitamin K supplement may also be given to those who have a Vitamin K deficiency due to liver or gut disease, or the long term use of some medications, such as certain antibiotics.

In addition, Vitamin K may also be used to prevent or reverse the side effects of bleeding associated with an overdose of blood thinners (e.g. warfarin).

How should I take/use this medication?

  • Do not stop taking your medication without checking with your healthcare professional.

  • Vitamin K may be given by mouth, with or without food (undiluted or diluted in a beverage e.g. orange juice)

    • Click on this link for the correct method of breaking and administering Vitamin K orally from glass ampoules:

  • Vitamin K may also be given via an injection to a muscle or a vein by your healthcare professional

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if:

  • You are allergic to this medication or any of the other ingredients of this medication

  • You are taking any other medications, including supplements, traditional medications and herbal remedies.

What are some common side-effects of this medication?


  • Pain, redness, or swelling at injection site

    • You may place a cold compress over the affected area for relief

    • You may take paracetamol for pain relief

  • Change in taste

    • Consult your healthcare professional if the symptoms do not go away or become bothersome.

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following:

  • Swollen face/eyes/lips/tongue

  • Difficulty in breathing

  • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately

What food or medication should I avoid when I take this medication?

When taking Vitamin K by mouth, space at least 2 hours before or after Orlistat, a medicine used to treat obesity. This is to prevent a reduction of Vitamin K absorption by Orlistat.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How should I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.


Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Oct 2022

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