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Vitamin K for newborn babies

All newborn babies are offered a vitamin K injection soon after they're born. This is to protect them from a rare bleeding disorder called vitamin K deficiency bleeding.

Before your baby is born, your midwife will tell you about vitamin K and ask you to sign a form. This is to say it's okay to give it your baby. It's your choice whether your baby gets the vitamin K injection or not.

Why your baby needs vitamin K

Vitamin K helps your baby's blood to clot and prevents serious bleeding.

Most babies are born with low levels of vitamin K. Because of this, they need extra vitamin K.

Vitamin K prevents a rare but serious bleeding disorder called vitamin K deficiency bleeding (VKDB). About 1 in 10,000 babies develops VKDB.

VKDB can cause brain damage or even death. Around 7 out of every 100 babies who develop VKDB will die. About 30 out of 100 will have brain damage.

How vitamin K is given

Your midwife will give your baby 1 injection of vitamin K in their thigh. This is the best way for your baby to get vitamin K. It's the quickest and most effective way of preventing them getting VKDB.

Your baby can also be given vitamin K through their mouth, using a syringe. This is less effective than getting it by injection. If your baby is given vitamin K this way, they'll usually need 3 doses.

They will get the first dose in the maternity unit or hospital soon after birth. The second dose will be given when they are between 4 and 7 days old.

If they are breastfed for more than half their feed, they'll get a third dose at home at 1 month.

If they are formula-fed, they won't need a third dose because vitamin K is added to formula.

Safety of vitamin K

Vitamin K has been used for many years in Ireland. It is routinely given to all babies with the consent of parents.

There are no known side effects to your baby. If you have questions about vitamin K, ask your midwife, obstetrician or GP.

It is important that you have all the information you need to decide what is right for your baby.

Whatever you decide, it is a good idea to write it in your birth plan and to make sure that your birth partner knows your wishes.

Signs of vitamin K deficiency bleeding (VKDB)

Babies with VKDB may start to bleed without a reason from their:

  • nose
  • mouth
  • umbilical stump (belly button)
  • bottom

A tiny number of babies may bleed somewhere else where you can't see, such as in their brain or gut. This can be dangerous and may be life-threatening.

VKDB is rare and usually only occurs between birth and 3 months old. Late VKDB can occur up to 6 months old.

Get urgent medical help

Urgent advice: Get urgent medical help from your nearest hospital emergency department that treats children if your baby:

  • has unexplained bleeding or bruising
  • is older than 3 weeks and is jaundiced
  • is younger than 3 weeks and their jaundice is getting worse
  • their skin is paler than usual (in darker skin you may notice their gums are paler than usual)
  • has blood in their poo, or their poo changes colour to a dark black colour like tar
  • is vomiting up blood
  • is drowsy and not waking for feeds
  • is not moving all 4 limbs
  • is very irritable
  • is having any seizures or fits


If your baby did not get the vitamin K injection, make sure to tell the doctors and nurses looking after them.

These symptoms could be signs of VKDB. It's easy to prevent this by giving 1 injection of vitamin K to your baby at birth.

Page last reviewed: 14 August 2019
Next review due: 14 August 2021

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 8.