The American Academy of Pediatrics has recommended a single intramuscular dose of vitamin K for newborns since 1961; however, in the last decade parents have increasingly elected to skip the shot.
Elizabeth Wolf , M.D., MPH, a pediatrician at Children's Hospital of Richmond at VCU and an associate professor in the Department of Pediatrics at Virginia Commonwealth University School of Medicine, led a nationwide study to understand the change in vitamin K deficiency (VKD) and vitamin-K-deficient bleeding (VKDB). The results were published today in JAMA Pediatrics .
"We knew from prior studies that vitamin K refusal had been increasing in the U.S., and we wanted to learn if there were any real-life consequences of this trend," Wolf said. "We found that the answer is undeniably yes, with the rates of VKD and VKDB multiplying over the course of our study."
Steven Woolf , M.D. director emeritus of the VCU Center on Society and Health and professor in VCU School of Medicine's Department of Family Medicine , was a co-author, along with Evan French, MS of VCU's C. Kenneth and Dianne Wright Center for Clinical and Translational Research , and Darya Shokouhi Niaki , Pharm.D., of the VCU School of Public Health's Department of Biostatistics .
Vitamin K deficiency and associated bleeding in infants
Vitamin K is essential for the activation of specialized proteins needed for normal blood clotting. Newborns have a deficiency of vitamin K because of inefficient transfer of vitamin K from the placenta, poor gastrointestinal absorption and low vitamin K content in breast milk.
Classical VKD, which occurs between 2 days and 1 week after birth, leads to bleeding of the umbilicus and bruising. Late VKD, occurring between ages 1 week and 6 months, carries a 30% to 60% risk of intracranial hemorrhage, which can result in seizures, permanent brain damage or death.
Despite this information, parents are increasingly refusing vitamin K injections at birth. Previous studies found that between 2017 and 2024 the proportion of newborns not receiving intramuscular vitamin K rose from 2.9% to 5.2%.
More than 11 million infants were studied with concerning results
Using a large national database with deidentified electronic health record information from health systems across the U.S., researchers analyzed records from more than 11 million infants aged 0 to 6 months born at 35 weeks' gestation or later who received care between 2017 and 2025.
Among the study's findings:
- The percentage of newborns who received injectable vitamin K decreased from 97.7% to 95.0%.
- The rate of VKD and VKDB increased by 216% and 347%, respectively.
- Only 40% and about 19% of infants diagnosed with VKD and VKDB, respectively, received vitamin K shots.
- Of those with VKD and VKDB, about 7% and 2%, respectively, also had a diagnosis of intracranial or intracerebral hemorrhage.
Researchers caution that the simultaneous decrease in vitamin K injections and increase in diagnoses of VKD and VKDB between 2017 and 2025 does not prove causality. However, Wolf notes that other explanations are unlikely because behaviors and diseases that increase the risk for VKD remained constant or decreased during this period.
Proper messaging to protect newborns in the years ahead
Refusal of vitamin K has risen as mistrust in doctors and public health professionals has grown. Like childhood vaccines, the researchers say that vitamin K has been "a victim of its own success," with many parents unaware that refusal of the shot can come with serious lifelong consequences.
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 says.
"We should continue to follow these trends moving forward since the rates of vitamin K deficiency and vitamin-K-deficient bleeding may continue to rise if vitamin K refusal keeps increasing. We need to better understand why parents are refusing vitamin K and what can be done to improve the uptake of this important medication," Wolf said.
"Similar to the recent measles outbreaks, we are seeing the real-world implications of growing mistrust of doctors and public health professionals. We need clear messaging from all levels of public health about the benefits of vitamin K administration for newborns."
