Vitamin K: a new reason to worry?

medium_4417602702 I have been asked a number of times recently whether my position on vitamin K has changed as a result of the US news story and related commentaries about a CDC (2013) report which raises concerns about an apparent increase in the number of babies who did not receive vitamin K and who go on develop bleeding disorders.

The answer is no.  I still think that parents have every right to make their own decision based on good information, which includes different perspectives and a fair appraisal of what we do and do not know.

I understand the value of these different viewpoints and respect the way in which people interpret evidence and information differently depending on their perspective, experiences and beliefs, so I am glad that there are other people out there who have different ideas from me.  For what it’s worth, I have a few thoughts to share on the subject.

Firstly, I absolutely don’t want to downplay the seriousness of neonatal bleeding or its consequences.  But we do also have to consider the bigger picture and the other possible consequences of giving babies a substance that they may not need.  In fact, only one in every several thousand babies is at risk of bleeding without vitamin K, and we may be able to identify some of the babies who may be at greater risk. The report and subsequent news story did not mention any of the details about the births of the babies who were admitted to the hospital, and so we do not know whether there were potential red flags that might have predicted a greater likelihood of problems (such as the babies having had traumatic births), or the babies having underlying conditions that could cause or contribute to bleeding (such as cholestatic disease).

small_89166669The emotive emphasis on the fact that all of the babies who were admitted had been born to parents who had declined vitamin K could be argued to have been unnecessary.  To my knowledge, none of the people who have concerns about the mass administration of vitamin K have ever denied its effectiveness.  Au contraire; it is highly effective.  It is the necessity and the possible unintended effects of this that are in question.  It stands to reason that, if a treatment is almost 100% effective, then those who have had the prophylaxis that is given to prevent it are highly unlikely ever to be admitted with the problem that it is given to prevent.  The only people who will be admitted with the problem are those who didn’t have the prophylaxis.  We should not be at all surprised, then, that all of the babies who have been admitted with bleeding were born to parents who declined vitamin K.  Rather, we should be surprised if this were not the case.

The reported increase does sound worrying, but we need far more analysis of the data before we can know what is really going on, and whether it is of concern.   It is entirely possible that the fact that these babies were all admitted within a few months of each other was coincidental.  There may be all sorts of things that could explain this.  I once worked at a large tertiary unit which, compared to the national average, had an unusually high proportion of women who experienced a particular pregnancy-related condition.  Were the women in that area particularly susceptible to that condition?  No, this apparent statistical anomaly occurred because the unit contained a staff member who was a world leader in the treatment of the condition, and women who were experiencing it thus came in from all over the country.  Of course, those working in the hospital concerned may already know the answer to this, but if the unit in question is one to which other units refer, or contains a specialist in the field, or if one or more of the cases occurred when other units were busier and unable to admit babies with serious bleeding, then these factors may become explanations.

One of the things that concerns me the most is the glossing over of the potential risks and unintended consequences of vitamin K.  I do not agree with those who say that there are no risks to giving vitamin K.  It is not that I am arguing that vitamin K is a highly risky drug; I merely think parents should know that there are possible risks to either course of action, and we do not have good enough data on the potential risks of vitamin K. In my view, making claims that any drug or substance is risk-free is just as irresponsible as not informing parents of the reasons for giving vitamin K and the things they need to watch out for if they decline it (which I discuss here).

Yes, some of the studies which were designed to assess the risks were not well designed (and have rightly been criticised) but they were carried out in the first place because of real concerns, and the fact that the studies weren’t helpful because the methodology was poor does not negate the original concerns.  We still have a need for good research on this area; there has never been a randomised controlled trial on this topic, many questions relating to issues such as whether certain groups of babies are more at risk than others are up in the air because we do not have decent evidence to know one way or the other and von Kries (1988) noted in the British Medical Journal that, although the evidence now pretty much rules out the risk of solid tumours, “a small risk of leukaemias cannot be excluded” (161).  He described the situation around vitamin K knowledge as “a Gordian knot [that] still awaits untying”.

Sadly, elements of this knot still remain impossibly tangled and our response to any increase in parents declining this intervention or any increase in the problem that vitamin K seeks to prevent should not be increasingly emotive information or attempts at persuading parents to accept or decline this substance on behalf of their baby but, instead, genuine acknowledgement of concerns and a pledge to actually do something about gathering the further knowledge that is so badly needed.


Centers for Disease Control and Prevention (CDC). Notes from the field: late vitamin K deficiency bleeding in infants whose parents declined vitamin K prophylaxis – Tennessee, 2013. MMWR Morb Mortal Wkly Rep. 2013;62(45):901–902.

von Kries (1988).  Neonatal vitamin K prophylaxis: the Gordian knot still awaits untying.  BMJ 316: 161-62.

A page containing links to my work on vitamin K can be found here.

photo credits: syringe/book by Jens Finke, baby by Etolane via photopin cc and cc

5 comments for “Vitamin K: a new reason to worry?

  1. Lynnette
    May 19, 2014 at 1:13 pm

    Seriously? It is a vitamin. Since when is a normal dose of a vitamin risky? We are talking about the potential for brain damage versus some theoretical risk of side effects. Yes it is rare. But given that the babies who do experience brain bleeding and the catastrophic results that can happen, i’m sorry, but it seems the height of stupidity to withhold this.

    • Heather
      May 25, 2014 at 10:13 pm

      Hi Lynnette,

      I don’t think that Sara is suggesting that it is withheld, but more that it is not ethically correct to say there are “no side effects”.
      Perhaps it’s more reading into the studies and information that is required by all of us involved in engaging parents in these decisions?

      “We’ve always done it” doesn’t really cut it in evidence-based midwifery, in my humble opinion

    • Erica
      June 16, 2014 at 7:12 am

      Lynnette, the shot of vitamin K that newborns receive is not a “normal dose of a vitamin”. It is actually 20,000X the amount of vitamin K normally present at birth. Yes. 20,000X. That was not a typo. This doesn’t necessarily equate into the shot being an awful, terrible, no good thing. But it’s definitely *not* at all in the same category as giving a child a Flinstone’s chewable.

    • kirsten
      July 25, 2015 at 4:02 pm

      a vitamin, yes, but a synthetic one and one that has a host of other additives as well. and why treat so many babies with a drug that is really being used to prevent an issue with so few. i am not opposed to a vitamin supplement to a baby, but there haven’t even been controlled studies looking at the potential risks of giving a substance that puts the level of vitamin k in babies 10,000 times the normal adult level. this seems ludicrous to me. why not study this and come up with a more appropriate dose. why not study this at all so as to have “evidence based” proof that it isn’t potentially harmful!!!

  2. Laura
    June 5, 2015 at 1:09 pm

    Hey Lynette,
    I don’t think Sara is arguing that it shouldn’t be given, it’s just that in light of the evidence, we can’t say it is risk free. Unfortunately, midwifery and obstetrics are plagued with techniques or procedures that might seem inocuous initially, but that years of research shows how it can have a detrimental effect when you look at the big picture.
    And the other thing, just because it is a Vitamin, does not mean it can’t be harmful. There are some vitamines that in too high concentracions might be harmful, as we are already getting them from our diet. Vitamin A in pregnancy would be an example of this.

Leave a Reply