Vitamin K for newborn babies to prevent vitamin K deficiency bleeding

Name of medicine

Vitamin K (also knows as phytomenadione)

Brand names: Konakion MM paediatric, Neokay capsules

Why is it important for my child to take Vitamin K?

• The body needs vitamin K to make proteins that help the blood to clot and to prevent bleeding.
• At birth, babies have only small stores of vitamin K.
• These stores build up once they baby starts feeding.
• If these stores become too low, the baby is at risk of vitamin K deficiency bleeding (VKDB).

What is Vitamin K available as?

• An injection of vitamin K into the muscle (intramuscular injection) soon after birth is recommended for most babies, because it works immediately and only one dose is needed.
• Vitamin K can be given be given as liquid drops by mouth, or may be injected into a vein (intravenous injection) in some situations.

When should I give Vitamin K

• The best way to give vitamin K is by intramuscular injection, which is done by a healthcare professional soon after birth. This is particularly important if you have had an assisted delivery (forceps or ventouse) as this may cause some bleeding.
• Vitamin K can also be given by mouth, although this works less well than by injection. If you choose oral administration, your baby will be given either:
  • Konakion MM Paediatric - given by a midwife or health visitor on the day of birth and again after 4–7 days. Babies who are exclusively breastfed will need another dose when they are 1 month old. (Formula feed has added vitamin K, so a third dose is not needed.)
  • Neokay - given on the day of birth by the midwife, and then you will give it once a week for 11 weeks.
• If your baby is born very early, or is unwell or small, an intravenous injection of vitamin K is recommended. This is given soon after birth, then again after 1 week and 4 weeks.
• Intravenous injection may also be recommended if the mother is taking medicines during pregnancy that affect vitamin K (e.g. for epilepsy or to prevent blood clotting).

How much should I give?

• If you have chosen oral vitamin K, your midwife or doctor will tell you how much to give.

How should I give Vitamin K?

• The Neokay vitamin K drops are best given immediately after a feed, as the fat in milk helps the body to absorb the vitamin.
• Cut the narrow tubular tip off the Neokay capsule. Squeeze the contents into your baby’s mouth so that it cannot dribble out. Make sure they have swallowed all the contents.
• Do not put the capsule in your baby’s mouth.
• Give the dose on the same day each week, to help you remember.
• You may want to set a reminder on your phone or make a note in your diary, as it is vital that your baby has all 12 doses (your midwife will give the first dose after birth).
• Make sure you give the whole dose each time, and that you give all 12 doses (one week apart)

When should the medicine start working?

• Intramuscular vitamin K protects against VKDB straightaway because it remains stored in the muscle.
• Oral vitamin K is absorbed more slowly than after injection so it will take longer for the vitamin K stores to build up and protect against VKDB.
• You will not see any difference in your baby, but the vitamin K will still be working.

What if my child is sick (vomits)?

• If your baby is sick or spits up less than 3 hours after having a dose of vitamin K, give them the same dose again.
• If your child is sick or spits up more than 3 hours after having a dose of vitamin K, you do not need to give them another dose on that day. Wait until the next weekly dose.
• If your child is sick again, seek advice from your doctor, pharmacist or hospital.

What if I forget to give it?

• If you forget to give an oral dose of vitamin K, give it as soon as you remember. Then continue to give the remainder of the doses as directed.

What if I give too much?

• You are unlikely to do harm if you give an extra dose of vitamin K by mistake.
• If you are concerned that you may have given too much, contact your doctor or local NHS services (details at the end of this leaflet).
• Have the medicine or packaging with you if you telephone for advice.

Are there any possible side effects?

• We use medicines to make our children better, but sometimes they have other effects that we don’t want (side-effects). However, vitamin K rarely causes any side-effects.
• Your baby may have some redness or swelling at the site of the injection.
• If you notice anything unusual and are concerned, contact your doctor. You can report any suspected side-effects to a UK safety scheme at https://yellowcard.mhra.gov.uk

Can other medicines be given at the same time as Vitamin K?

• You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.

• Vitamin K should not be taken with some medicines. Tell your doctor or pharmacist about any other medicines your child is taking before giving Vitamin K.

Check with your doctor or pharmacist before giving any other medicines to your child. This includes herbal and complementary medicines.

How do I weigh up the benefits and risks of giving vitamin K?

It is important to understand the benefits of vitamin K and the potential risks of choosing not to give it to your baby.

• The risk of VKDB is highest soon after birth but continues for up to a year for babies who have not received vitamin K.
• Some babies with VKDB may get only mild bruising. However, VKDB may cause bleeding from the mouth, tummy button (umbilicus) or back passage. Your baby may vomit blood, have blood in their poo, get nosebleeds or have unexplained bruises. If symptoms are not treated, they are at risk of bleeding in the brain, which can cause permanent brain damage or death.
• Classical onset VKDB occurs within a week of birth and affects one in every 2,000 babies.
• Late-onset VKDB can occur at any time between a week and a year after birth and often develops without warning. More than half of babies have bleeding in the brain. Late-onset VKDB affects about 1 in 11,000 babies.
• Giving vitamin K at birth reduces the risk of VKDB to 1 in 100,000, meaning VKDB is almost completely prevented, which is why the treatment is recommended.
• Some parents worry that the intramuscular injectionis painful for their baby. The injection may cause a little pain and the baby may cry, but the pain is short-lived and the baby can be easily soothed. They won’t remember the injection.
• Some parents have decided not to give their baby vitamin K after finding comments on the internet about a possible connection with cancer. This idea came from a small study carried out over 30 years ago which suggested that children who received vitamin K might have an increased risk of blood cancer. However, many more studies have since explored this possible connection, and none has found any evidence of a link.

Is there anything else I need to know about this medicine?

• If your baby has difficulty feeding, talk to your health visitor or doctor to make sure they are getting enough vitamin K.
• If you decide that you do not want your baby to have a vitamin K injection, or you prefer to give oral vitamin K, it is important to be consider whether you would change your mind if a healthcare professional recommends the injection (into the muscle or a vein) following delivery.

General advice about medicines

• If you are not sure a medicine is working, contact your doctor but continue to give the medicine as usual in the meantime. Do not give extra doses, as you may do harm.

• Only give this medicine to your child. Never give it to anyone else, even if their condition appears to be the same, as this could do harm.

• Make sure that the medicines you have at home have not reached the ‘best before’ or ‘use by’ date on the packaging. Give old medicines to your pharmacist to dispose of.

Where should I keep this medicine?

• Keep the medicine in a cupboard, away from heat and direct sunlight.

• Make sure that children cannot see or reach the medicine.

• Keep the medicine in the container it came in.

• You may need to keep liquid medicine in the fridge – check the instructions on the bottle. Make sure the medicine does not freeze.

Who to contact for more information?

Your doctor, pharmacist or nurse will be able to give you more information about Vitamin K and about other medicines used to treat Vitamin K deficiency bleeding.

Copyright disclaimer

Version [1]. © NPPG, RCPCH and WellChild, all rights reserved. Review by September 2026.

The primary source for the information in this leaflet is the British National Formulary for Children. For details on any other sources used for this leaflet, please contact us through our website, www.medicinesforchildren.org.uk.

We take great care to make sure that the information in this leaflet is correct and up-to-date. However, medicines can be used in different ways for different patients. It is important that you ask the advice of your doctor or pharmacist if you are not sure about something. This leaflet is about the use of these medicines in the UK, and may not apply to other countries. The Royal College of Paediatrics and Child Health (RCPCH), the Neonatal and Paediatric Pharmacists Group (NPPG), WellChild and the contributors and editors cannot be held responsible for the accuracy of information, omissions of information, or any actions that may be taken as a consequence of reading this leaflet.