Vitamin K for Newborns

Vitamin K (Vit. K) is a fat soluble substance and it plays a role in the blood clotting process. It is in foods such as green leafy veggies. Babies are ‘deficient’ in Vit. K but it is not understood why. This ‘deficiency’ can result in a rare but serious Haemorrhagic Disease of the Newborn (HDN) aka Vit. K Deficiency Bleeding (VKDB).

In the UK approximately 1 in 10,000 babies are affected by this disease per year. Some babies are at higher risk of HDN, ie:
  • Babies who are preterm (born before 36 weeks)

  • Babies born via instrumental birth or C-Section

  • Babies born with breathing difficulties/ low APGAR score

  • Babies with liver disease

  • Babies born to mothers on anti-coagulants, anti-convulsants or treatment for TB.


Note, however, that about 16% of babies affected by HDN did not have any known risk factors.

The HSE & the NICE guidelines recommend offering all parents prophylactic Vit. K to reduce the incidence of Vit. K deficiency.


OPTIONS of Administration:

  • Option 1: 1mg given in the baby’s thigh shortly after birth.

  • Option 2: 2mg given into baby’s mouth shortly after birth. Further dose b/w 4-7 days old & again at 28days old.

  • Option 3: Parents can decline to give their baby Vit. K.



Myth buster: In the 90’s there was a suggested link between Vit. K injection and childhood cancer. However, in 1997 it was concluded by an expert group that the available data did not support this idea. Recently, a study of more than 4,000 babies reported no association with Vit. K administration and cancer.



Side effects of Vit. K injection would be pain, infection of injection site & bleeding at injection site. Very rare side effects can include swelling of the lips, mouth, throat and face (this may cause breathing difficulties). The manufacturers also note in rare cases a reaction may occur at the injection site which causes a rash & this can be severe enough to cause scarring. They also note that there is a small increase of neonatal jaundice in babies who have had Vit. K.


Signs & Symptoms of HDN include: nose bleeds, blood in urine/stools, oozing from the cord, unexplained bruising or the failure to clot blood after a blood test. If this happens, urgent referral to a paediatrician is required.


As with any intervention, parents must make a decision as to what is the best option for them. Some places to get more information about the Vit. K medication for newborns would be:


Evidence on: The Vitamin K Shot in Newborns - Evidence Based Birth®

Vitamin K - Dr Sara Wickham


Happy Reading!

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