This is still a fairly rare phenomenon in my hospital, but it does seem to increasing slightly here, as it is just about everywhere else.

The science is settled, transplacental transfer of vitamin K is extremely limited, hepatic stores at birth are very low, and human milk contains extremely low concentrations of vitamin K. In later life, most of our vitamin K2 is produced by intestinal microbiota, including by our friends the Bifidobacteria, as well as Bacteroides and Prevotella, but we don’t have many of those present at birth or over the first few days. Routine supplementation with intramuscular vitamin K is an intervention with amazingly positive risk/benefit balance, which has proven its worth over decades. Like many other preventive interventions, the success of routine vitamin K prophylaxis is probably part of the reason for the current situation. In addition, the relative rarity of what is now called Vitamin K Deficiency Bleeding (VKDB, which I think is a better name than Haemorrhagic Disease of the Newborn) means that most families will never have heard of a case.

A new publication from Sweden (Simatou E, et al. Vitamin K Prophylaxis in Newborns and Bleeding in Infancy. JAMA Pediatr 2026) has the usual limitations of all large database studies, uncertainty about the accuracy of each individual data entry, diagnostic standards etc. But it points out that infants (>35 weeks GA) without a record of neonatal IM vitamin K prophylaxis (checkbox left empty) had a much higher rate of having an ICD-10 diagnosis of “any bleeding episode” prior to 6 months of age. They also had a much higher risk of having intracranial bleeding, or the combined outcome “death or bleeding”. When the analysis was restricted to the first 28 days of life the associations were even stronger. The greatest difference between groups with and without IM vitamin K administration documented was in “death or intracranial bleeding” in the 1st 28 days of life: 0.1% in infants with VitK, 1.5% in those without. Of course, most of those deaths would have nothing to do with vitamin K, but they should be equal in the 2 groups. However, when I look at these new Swedish data in detail, there are very many more deaths among the infants without a record of Vitamin K administration: 1300/100,000 compared to those who received vitamin K, 50/100,000, before 28 days of age (calculated by subtracting ICH from “death or ICH”) which I don’t fully understand.

Other data show that babies who don’t get vitamin K also are more likely to be born at home, more likely to not have Hepatits B or other immunizations (Loyal J, Shapiro ED. Refusal of Intramuscular Vitamin K by Parents of Newborns: A Review. Hosp Pediatr. 102020. p. 286–940 and, I would think, more likely to be exclusively breast fed, which increases the chances of VKDB, as there is much more vitamin K in artificial formula.

That review article on refusal rates (Loyal et al) also reviewed the published reasons parents gave for not wanting prophylaxis. they broke them into 3 categories. 1. Concern of harm from the injection (from the preservatives or from pain, or because the dose is too high, or it causes cancer). 2. Desire to be natural, often assuming that being “natural” meant that vitamin K insufficiency is not a problem. 3. Belief in alternative prophylaxis, either oral, or maternal or something else.

As I was preparing this, I came across an excellent review article (Mirone A, et al. Vitamin K Prophylaxis in Newborns: A Narrative Review of the Molecular Basis, Clinical Evidence, and Comparative Effectiveness of Intramuscular Versus Oral Administration and Parental Hesitation. Int J Mol Sci. 27 2026) which led to several of the references I have included.

What to do about this worrying and dangerous trend?

Education during pregnancy is essential, but I am doubtful that will have a major impact on the current trend. Education at birth is also important, and nurses have a major role to play (Holley SL, et al. Educating Parents on Vitamin K Prophylaxis for Newborns. Nurs Womens Health. 2020;24(4):283–93), but again I am sceptical that many minds will be changed.

I just did a quick search on Facebook about Vitamin K in babies, fortunately the very first result (maybe that’s just my algorithm) was from the excellent Jessica Knurick, whose clear evidence-based videos are always spot-on. The remainder range from clear support for the science to fear-mongering nonsense, including one from a prominent physician fear-monger who claims that God wouldn’t make babies short of vitamin K, I don’t know how he explains any congenital anomalies. Other posts frequently talk about how blood should be “thinner” at birth, often stating that vitamin K increases viscosity preventing the good cells from doing their work. Like a lot of medical pseudoscience on the internet, the nonsense is frequently repeated by other “influencers” who are usually selling something, even if its only subscriptions to their channel. They also often claim that physicians are making the vitamin K recommendation because of a personal gain. How we are supposed to be making money from recommending universal IM vitamin K prophylaxis, I don’t know.

One hospital in Tennessee, where there was a cluster of cases, introduced a mandatory information sheet detailing the risks of IM vitamin K refusal, and required signing an opt-out form, which is entered into the infants chart. Intramuscular vitamin K administration should be automatic, and require an opt-out for reluctant parents, whether requiring that parents read a document and sign a form will help, I am unsure. It has been proposed that parents should not even have the right to opt out (Isennock SM. The Legal Limits of Parental Autonomy: Do Parents Have the Right to Refuse Intramuscular Vitamin K for Their Newborn? HCA Healthc J Med. 42023. p. 5–11), as vitamin K is safe and effective and we need to protect newborns against badly informed parents; even though I have a little sympathy for that attitude, I don’t think its likely to get very far.

As I was preparing this I came across new publications about the resurgence of Tetanus (Edwards KM, Rathore MH. Resurgence of Tetanus-Why the Vaccine Remains Instrumental. JAMA. 3362026. p. 99–100), and meansles, on the CDC measles surveillance page, which notes that there are already more measles outbreaks and individual cases by June this year than in the whole of 2025, which was already 10 times higher than 2024.

I am really at a loss to know how to approach the uncertainties of certain parents, the few who are rabidly anti-science, and the many who are just confused and hesitant. Requiring social media companies to reign in the misinformation would be a good idea, but is not likely to get very far with extreme right wing conspiracy theorists being responsible for the most potent communication vehicles that humanity has ever known.

The first step for an individual case of vitamin K refusal has to be to recognise that all parents want the best for their babies, and that most of them will have no idea about the devastating consequences of VKDB. They will not understand the deaths and the brain injuries that can occur, or that they can be almost entirely prevented by a brief painful injection of a vitamin.