Vitamin K shot uptake fell as infant bleeding cases rose, JAMA Pediatrics study finds

The share of newborns receiving injectable vitamin K fell from 97.7% to 95.0% between 2017 and 2025, while the rate of vitamin K–deficient bleeding rose about 347% over the same years, according to a JAMA Pediatrics study reported by Virginia Commonwealth University on Nov. 5.

Elizabeth Wolf, M.D., a pediatrician at Children’s Hospital of Richmond at VCU and an associate professor in the VCU School of Medicine Department of Pediatrics, led the study. Co-authors named by VCU include Steven Woolf, M.D.; Evan French; and Darya Shokouhi Niaki, Pharm.D.

What the study found

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.

Over those years, the rate of vitamin K deficiency, or VKD, increased by 216%. The rate of vitamin K–deficient bleeding, or VKDB, increased by 347%.

Among infants diagnosed with VKD, only 40% had received vitamin K shots. Among those diagnosed with VKDB, about 19% had received the shots.

Of infants with VKD, about 7% also had a diagnosis of intracranial or intracerebral hemorrhage. Of those with VKDB, about 2% also had that diagnosis.

Why newborns get the shot

The American Academy of Pediatrics has recommended a single intramuscular dose of vitamin K for newborns since 1961.

Newborns are born with low stores of vitamin K, which the body needs for blood clotting, VCU said. Classical VKD appears 2 days to 1 week after birth, with bleeding at the umbilicus and bruising. Late VKD appears 1 week to 6 months after birth and carries a 30% to 60% risk of intracranial hemorrhage, which can cause seizures, permanent brain damage or death.

VCU also cited earlier studies showing that between 2017 and 2024 the share of newborns not receiving intramuscular vitamin K rose from 2.9% to 5.2%.

Caution on cause

The researchers said the simultaneous drop in injections and rise in diagnoses does not prove causality. Wolf said other explanations are unlikely because behaviors and diseases that raise VKD risk stayed constant or fell over the study period.

“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.”

Wolf said clear public health messaging is needed. VCU reported that she compared the trend to measles outbreaks and growing mistrust of doctors and public health professionals.

Parents preparing for delivery can ask the birth hospital whether injectable vitamin K is offered as part of newborn care. That is an information step, not medical advice.