Nationwide data from over 5.2 million infants reveals a troubling correlation: as the rate of newborn vitamin K injections has declined, life-threatening bleeding events have nearly doubled, CIDRAP reported. The study, analyzing health records from 2017 to 2025, found that while 97.7% of newborns received the shot in the earlier years, that number dropped to 95.0%. Over the same period, the rate of bleeding in infants who did not receive the injection increased from 225.3 to 394.0 per 10,000 births.
This investigation, published in JAMA, provides the first comprehensive documentation of a nationwide decline in vitamin K administration and a simultaneous increase in bleeding risks.
Refusing the Vitamin K Shot Raises Deficiency Risk
The refusal of the intramuscular vitamin K dose has steadily increased over the last decade. According to the JAMA study, the proportion of parents declining the shot for their newborns rose from 3.1% in 2017 to 6.8% by the end of 2025. This upward trend is mirrored in other analyses, with VCU Health noting a rise from 2.9% to 5.2% between 2017 and 2024. This growing hesitancy is directly linked to a stark rise in vitamin K deficiency (VKD) and vitamin K deficiency bleeding (VKDB).
The clinical implications are severe. A separate study, also published in JAMA, found that among infants diagnosed with VKD, only 40% had received the recommended shot. For those with VKDB, the figure was even lower, at just 19%. “We knew from prior studies that vitamin K refusal had been increasing in the US, and we wanted to learn if there were any real-life consequences of this trend,” lead author Elizabeth Wolf, MD, MPH, said. “We found that the answer is undeniably yes, with the rates of VKD and VKDB multiplying over the course of our study.”
The most dangerous outcome of VKDB is intracranial hemorrhage. The research shows that 7% of infants with VKD and 2% of those with VKDB were also diagnosed with bleeding in or around the brain. These events carry a high risk of permanent neurological damage or death. As reported, “about 1 in 5 babies who develop VKDB die. Among those who survive, roughly 40% suffer long-term neurological damage, including seizures or paralysis.”
US infant bleeding episodes jump as vitamin K refusals rise, two studies find https://t.co/SQU46NYGT4
Skipping the Vitamin K Shot Increases Bleeding Risk
- Skipping the vitamin K shot at birth significantly increases an infant’s risk of dangerous bleeding, with rates nearly doubling in those who don’t receive it.
- The most serious risk is bleeding in the brain, which can lead to seizures, permanent brain damage, or death, and often occurs with no warning signs.
- The American Academy of Pediatrics has recommended this single shot for all newborns since 1961.
A Tale of Two Risk Profiles
For every 10,000 newborns who received the vitamin K shot, the rate of bleeding events increased from 136.6 to 221.8 over the study period. In stark contrast, for every 10,000 newborns who did not receive the shot, the rate of bleeding rose dramatically from 225.3 to 394.0.
When researchers controlled for factors like gestational age, sex, and maternal characteristics, they found that babies without a documented vitamin K shot had a 47% higher risk of any bleeding event. The risk of life-threatening intracranial bleeding was more than twice as high, with 33 cases per 10,000 births among unvaccinated infants compared to 13 per 10,000 among those who received the shot.
Newborns are born with a deficiency of vitamin K because it doesn’t transfer well from the placenta, their intestines don’t absorb it well, and breast milk contains very little of it. Vitamin K is essential for the liver to produce clotting factors. Without it, an infant’s blood cannot clot properly, leading to spontaneous and often uncontrolled bleeding. This condition, known as vitamin K deficiency bleeding (VKDB), can manifest as bruising, bleeding from the umbilicus, or, most catastrophically, intracranial hemorrhage.
| Medical Outcome | Infants Without Vitamin K Shot (Per 10,000) | Infants With Vitamin K Shot (Per 10,000) |
|---|---|---|
| Bleeding Events (2017 Rate) | 225.3 | 136.6 |
| Bleeding Events (2025 Rate) | 394.0 | 221.8 |
| Intracranial Hemorrhage | 33.0 | 13.0 |
The Role of Public Health Communication
Researchers draw a parallel between the current vitamin K refusal trend and the recent measles outbreaks, linking both to a growing mistrust of medical professionals and public health institutions. “Similar to the recent measles outbreaks, we are seeing the real-world implications of growing mistrust of doctors and public health professionals,” Wolf said. “We need clear messaging from all levels of public health about the benefits of vitamin K administration for newborns.”
The editorial accompanying the JAMA study calls for a unified effort from all healthcare specialties—including pediatrics, obstetrics, and nursing—to communicate the risks clearly. The authors suggest that the vitamin K shot, much like childhood vaccines, has become “a victim of its own success,” with many parents unaware of the severe, lifelong consequences of refusal because the condition it prevents is now rare precisely because the shot is widely used.
VCU Health highlights that late-onset VKD, which occurs between one week and six months of age, carries a 30% to 60% risk of intracranial hemorrhage. The study’s authors stress the need for continued education so families understand that this protection is vital long after the first few days of life.
US infant bleeding episodes jump as vitamin K refusals rise, two studies find https://t.co/dUq0oOqEzT
When to Consult a Doctor About the Vitamin K Shot
The vitamin K shot is recommended for all newborns and is considered extremely safe. There are very few situations where it would be contraindicated.
Research Funding and Future Directions
The research was conducted using a large national database of electronic health records, providing a sample size of over 11 million infants born at 35 weeks’ gestation or later between 2017 and 2025. This data was collected from health systems across the United States, allowing for a broad, real-world analysis.
While the correlation is undeniable, researchers caution that the study does not definitively prove causality. The simultaneous decline in vitamin K shots and the rise in bleeding events strongly suggest a link, but further study is needed to fully understand the nuances of this relationship. “More research is needed to identify the best ways to emphasize the seriousness of vitamin K deficiency and promote the use of vitamin K in newborns,” Wolf stated.
As one researcher put it, armed with the data from this study, clinicians can now more confidently communicate the protection provided by intramuscular vitamin K prophylaxis.
What the hell is vitamin K? I never knew it existed. Here's why it's important for newborns: Vitamin K is required for the liver to make several important clotting factors, including II, VII, IX, and X. Without enough vitamin K, blood does not clot normally. A new JAMA Pediatrics… https://t.co/64Ul7hnpmV
References
Earlier coverage: Vitamin K Refusals Rise as Infant Bleeding Cases Surge in US, Studies Find
Fewer babies are getting a 60-year-old, lifesaving shot, and they are bleeding because of it. A new JAMA study published today looked at 5.2 million US newborns born between 2017 and 2025. The findings should alarm every parent, pediatrician and policymaker. 📈 Refusals more… pic.twitter.com/sTZVKEUVRa
