CHICAGO, Nov. 5 — Rates of life-threatening hemorrhage among U.S. infants have risen sharply since 2017 as parents increasingly refuse protective doses of vitamin K for newborns, a trend that coincides with a growing wave of distrust of vaccines and other neonatal interventions, according to two studies released Thursday.
These studies are the first to show that bleeding rates among American infants have increased alongside increasing refusals of vitamin K injections.
Babies are not born with enough vitamin K, an essential nutrient that helps blood clot, and vitamin K injections at birth have been the standard for more than 60 years. As a result, the U.S. Centers for Disease Control and Prevention does not track rates of vitamin K refusal or bleeding.
Vitamin K refusals have increased steadily since the Covid-19 pandemic, but accelerated under Health Secretary Robert F. Kennedy Jr., who spent decades sowing distrust in vaccines before taking the nation’s top health job. It has since dropped recommendations for children for six vaccines. Changes to the childhood vaccination schedule are on hold due to a legal challenge. Health experts say these mixed messages have left many parents skeptical about routine treatments for newborns, including vitamin K.
A Department of Health and Human Services spokesperson said the CDC still recommends vitamin K shots for newborns, but declined to say whether the agency would begin tracking rates of vitamin K refusal or bleeding events.
A study published in JAMA last December by Dr. Kristan Scott and colleagues at Children’s Hospital of Philadelphia showed that more than 5% of American babies will not receive vitamin K in 2024, a 77% increase since 2017.
The latest data, published in JAMA and JAMA Pediatrics, show that vitamin K refusal rates have continued to climb and begin to connect the dots between growing refusals of the essential vitamin and increased bleeding episodes.
Although these studies do not prove causation, the fact that bleeding rates increased so dramatically at the same time that vitamin K refusals and deficiencies increased is significant, said Dr. Steven Woolf, an epidemiologist at Virginia Commonwealth University, whose study was published in JAMA Pediatrics.
Providing vitamin K shots at birth has been the standard of care since 1961. “Now we’re moving away from that and we’re seeing the consequences,” he said.
Woolf and her colleagues studied the medical records of 11 million infants six months or younger between 2017 and 2025. During that time, the percentage of newborns given a vitamin K injection increased from 97.7% to 95%, while the rate of bleeding linked to vitamin K deficiency nearly quadrupled and appeared to be accelerating.
Out of more than 11 million births, there were a total of 5,217 bleeding events during this multi-year period.
“The rate in 2025 was about double what it was in 2024,” Woolf said.
The team noted that the 2025 peak coincides with an erosion of trust in public health following the COVID pandemic, growing vaccine hesitancy, and growing parental skepticism of interventions on newborns.
An exclusive analysis for Reuters of more than 1 million births nationwide by health data and analytics firm Truveta found that the percentage refusing vitamin K accelerated sharply in the first half of 2026, jumping more than 57% from January to June.
In Scott’s new study, published in JAMA, the team analyzed the medical records of more than 5.2 million U.S. infants born between 2017 and 2025.
During this period, the rate of newborns who did not receive a vitamin K injection more than doubled, from 3.1% in 2017 to 6.8% in 2025. It also jumped from the refusal rate of 5.1% at the end of 2024.
Babies who did not receive a vitamin K injection had a 47% higher risk of bleeding in the first 6 months of life than babies who did.
They also had more than twice the risk of brain hemorrhage in their first six months and death with a diagnosis of hemorrhage during their hospital stay after birth.
The authors calculated that for 114 newborns who do not receive a vitamin K injection at birth, one additional bleeding event would occur.
In June, Rep. Kim Schrier of Washington and Sen. Angela Alsobrooks of Maryland, both Democrats, called on the CDC to start tracking these bleeding events.
Dr. Elizabeth Wolf, a pediatrician at Richmond Children’s Hospital who led the VCU study, said the findings call for clear messages from all levels of public health about the need for vitamin K.
“Like recent measles outbreaks, we are seeing the real-world implications of a growing distrust of doctors and public health professionals,” she said.
Gn Health
