Vitamin K and Your Newborn

V I T A M I N  K  A N D  T H E  N E W B O R N

Babies are born with proportionally low vitamin K. We don’t know why yet, although there’s a few theories that it could be due to babies being born without all their systems fully functioning, or some kind of residual consequence of some other mother-baby mechanism. As mothers need to be intaking high doses of vitamin K for it to pass through breastmilk in sufficient quantities to protect their baby it seems unlikely to be an evolutionary response although my anthropological days were left behind at uni so, I may well be wrong.

Vitamin K helps blood to clot and prevent uncontrolled bleeding. Due to low vitamin K in babies, they’re at risk of something called ‘Vitamin K Deficiency Bleeding’ or VKDB. Some of these at risk babies have known risk factor but about a third don’t. This includes what type of birth the baby experienced, as it had been mooted at one point that assisted deliveries and caesareans increased the risk.

We started giving babies vitamin K after a Swedish study in 1944 was released which showed a 5 times reduction in newborn deaths of 2-8 day old babies due to uncontrolled bleeding. Manufacturing and commerciality interests pushed the dose given higher which triggered their own problems in the baby, so the dose was reduced back down and remains at 1mg although this is still twice as much as was given in the original study. At this time it was only being given to babies with suspected risk factors of bleeding, however in 1978 a study was released which discovered that late onset VKDB was a problem for exclusively breastfed babies and very quickly it became policy to universally offer to administer vitamin K. A small study did indicate that parents who refused to give their babies a vitamin K dose could raise the levels of vitamin K sufficiently to pass through breastmilk at protective quantities by the mother taking a supplement of at least 5mg daily.

Vitamin K is usually given via one injection within 24 hours of birth, although parents have the option to have oral doses given instead. If given orally this is done over the course of 3 doses, 2 of which are normally given to the parents to give at home. Side effects of the injection are a potential allergic reaction to the ingredients, or a small reaction at the site of the injection, plus of course a small amount of pain when carrying out the injection itself. The oral dose isn’t quite as effective at minimising the risk of VKDB and there’s the potential for further doses to be forgotten to be given in the sometimes chaotic environment of a newborn household.

One of the concerns some parents have about vitamin K doses is that a 1992 study was released that indicated an increased risk of cancer in children. Helpfully most UK health authorities and authoritative bodies made no official statements to help families make their decisions but instead fence-sat and passed the buck spectacularly to parents. Further studies showed that the risk of tumours remained the same whether children received vitamin K or not, however remained unclear about the increased risk of developing leukaemia. However, the most recent studies and reviews have concluded categorically that there are no links between vitamin K and an increase of cancer of any types.

So what are the actual statistical risks we’re looking at? The most recent studies show the numbers as follows:

  • Untreated babies risk of developing VKDB: 4.4-10.5 per 100,000
  • Oral treatment: 1.4-6.4 per 100,000
  • Intramuscular treatment: 0-0.62 per 100,000

Although small risks anyway, by choosing vitamin K to be given by injection the risks are all but eliminated.

If you choose to decline vitamin K there are things that you should watch out for in your baby. These are:

  • Active bleeding from the nose, mouth, gums, umbilical stump or any treatment site (heel prick test for example)
  • Blood present in urine, faeces, or vomit
  • Unexplained bruising or bigger than expected bruising (at a vaccination site for example)
  • – The fontanelle (soft spot of the head) appearing different to normal (which could indicate bleeding on the brain)
  • If baby starts acting differently; although this is a particularly difficult one as baby’s not been around long enough to have a ‘norm’.

As an aside, some trusts will refuse to divide a tongue tie if your baby hasn’t received vitamin K, so something to bear in mind.

As ever, this is my interpretation of what I’ve read and understood, and so any mistakes are my own only. My resources for this topic are below.

NICE Guidelines

Evidence Based Birth

Article with paediatrician E Hey in BMJ

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