Four vitamin K myths – and the truth

I want to address some vitamin K myths.

Because if there’s one birth-related topic on which myths abound, it’s the giving of vitamin K to newborn babies.

Vitamin K is given to prevent babies from getting a rare but potentially fatal bleeding disorder.

This disorder is called vitamin K deficiency bleeding, or VKDB. It occurs in about 1 in 11,000 babies.

Vitamin K can be given by intramuscular injection or orally (by mouth). Intramuscular vitamin K is usually given just after birth. Oral vitamin K tends to be given in a series of doses over the first few weeks of a baby’s life.

Vitamin K has been routinely offered in high-income countries for decades now, but it has also been controversial for much of that time. You can find out more of the key facts here.

I’ve been speaking, researching and writing about vitamin K for more than 25 years now. And one of the key things that I talk to colleagues about is just how many inaccurate blog posts and information leaflets are out there.

The inaccurate ones can be inaccurate in one of two very different ways.

Some are medically-focused and fear-based. These overplay the risks or cite unusual data without looking at the issues critically, or in depth.

But others downplay the risks and give a different type of inaccurate information.

Both are written by people who are well-intentioned. Unfortunately, some sources are biased, and many are using out-of-date information. Some writers are not knowledgeable enough about the issues. Often, they have summarised or copied someone else’s work (sometimes mine) and don’t really understand the research or the issues well enough themselves. So they make mistakes. 


Myths abound…

These issues aren’t unique to information about vitamin K. But vitamin K is a topic where inaccurate information seems to abound.

The topic hit the headlines a few years ago, when some research suggested that vitamin K may cause problems for babies. The resulting debate was complex, and many people misunderstood the nuances of it. (I needed to write a whole section in my book to explain it properly). This isn’t uncommon, especially when the mass media get involved. But a lot of sources still cite information on the debate which is almost-but-not-quite accurate.

Other aspects of our knowledge has grown and changed over the past few years. But some people share what they were taught, or what they have read elsewhere, and don’t think to look for new or better information.

So here I’m sharing the four most common vitamin K myths in the hope that this helps to set the record straight.

If you’re interested in this topic, you might also like to visit my vitamin K information hub, which links to several other articles and blog posts as well.


Myth 1: Vitamin K is a vaccine

It’s not uncommon to read that vitamin K is a vaccine.

It’s not.

Like some vaccines, vitamin K can be given by injection, although it can also be given orally (by mouth).

Like vaccines, vitamin K is given in the hope of preventing a problem/disease from occurring.

But it’s not a vaccine.

It’s a vitamin.

It doesn’t work to build antibodies.

Injectable vitamin K is a synthetic form of a vitamin which naturally occurs in some plants and vegetables. If it is given to a baby, it gives the baby a large reserve of vitamin K. You might hear it called a depot. And that reserve will help if a baby is one of the rare babies who develop blood clotting problems.

But yes, like with vaccines and all other medicines, there are pros and cons, which you’ll want to find out about before you decide if you want to give it to your baby.

But let’s be clear about what it is and isn’t, and it’s definitely not a vaccine.


Myth 2: the risk of VKDB has shot up in recent years

A few years ago, a hospital in Tennessee experienced a higher-than-usual number of babies who had experienced VKDB.

Doctors and researchers – quite rightly – wrote about this, because they were concerned.

They published papers which said that the risk of VKDB was much higher than we had previously thought. And some people added this to the information that they were sharing without looking too closely at the bigger picture.

I think the bigger picture is always important.

Context is everything, especially when we get new or surprising information. It’s always important to consider the bigger picture; to analyse and evaluate new information in relation to what else we know. And this was very surprising information, so it was important to ask some questions about it.

Was the risk going up elsewhere in the world?


Was it really likely that the risk would increase so much in such a short time?

Probably not.

Was it possible that this was an unusual cluster?

A statistical anomaly, or something very localised rather than a massive change in the risk that babies faced?


I wrote about this in detail in my book, if you’re interested in learning more about this.

But, in a nutshell, if tens of sources from around the world agree that the risk is one in several thousand and one hospital suddenly sees a few cases in a short time, it’s more likely that the one hospital is having an unfortunate run of VKDB than that the rest of the data are wrong.


Myth 3: Vitamin K is more likely to be needed if birth is traumatic

We used to think this was the case, but we now know that it’s not true.

In fact, the kind of bleeding that vitamin K is given to protect against can occur after any type of birth.

Including gentle birth, home birth, water birth, caesarean birth, instrumental birth, hospital birth, all-fours birth, squatting birth, birth centre birth … literally any type of birth you can think of.

Please, if you see this information somewhere, let the author know that it’s not true.

It’s not okay for parents to think that their baby is safer because they were born gently or at home, when that’s actually not the case. The chance of VKDB is still very low, but it’s important that parents have the facts.

A related question is whether a baby who has experienced bruising at birth always needs to be given vitamin K. I have not seen research which has specifically looked at this question. This is partly because the vast majority of paediatricians and guideline-making bodies recommend vitamin K for all babies. So there is very little research considering babies in specific situations. But it is hard to imagine any health professional not deeming a baby who is experiencing bleeding or bruising to be at potential risk of a bleeding disorder.

By challenging this myth, we’re not saying that babies who have bruising are actually fine.

The myth being challenged is that vitamin K is needed only if birth is traumatic.


Myth 4: The need for vitamin K is caused by medicalisation

Another common myth is the idea that the need for vitamin K is caused by medicalisation, or medical management of physiological birth.

Common ‘culprits’ include managed birth, managed third stage and early cord clamping.

Now this is a tricky one, because it is a myth in the way in which most people discuss it.

But it’s also something that needs more research, as it may be partly true in some cases.

But in general, I think we need to consider it a myth, and there are a couple of issues to know about here.

As I’ve mentioned in myth 3, we know that VKDB can occur after very gentle, unmedicalised birth.

In fact, because families who choose unmedicalised birth may also be likely to decline things like vitamin K, we’re more likely to see VKDB in babies born this way. That is not because it’s more risky. It’s because parents who opt for a more medicalised approach are more likely to give their babies vitamin K.

There are definitely conditions and outcomes which are caused by overmedicalisation, but VKDB isn’t one of them.

VKDB is a rare disorder and we don’t know enough about what causes it.

That’s why I’m saying that we can’t completely rule out that medicalisation may be a factor. It’s possible that, in some cases, medical intervention may play a part. But it’s very unlikely to be a simple, straightforward relationship. If it was, we would have spotted it by now.

Again, it’s inaccurate to tell to parents that a non-medicalised birth means a lower chance of VKDB. The chance of VKDB is really low to begin with. If you want to challenge the medical approach to offering vitamin K routinely, do it on the basis that we are using a sledgehammer to crack a nut without adequate trials of efficacy. Challenge the fact that there hasn’t been enough focus on exploring safety. But it’s not accurate to blame medicalisation for VKDB; it’s more complex than that.


If you’d like to read more about vitamin K, here’s my book.


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