Rates of life-threatening bleeding in US infants have spiked since 2017 as parents increasingly refuse protective newborn doses of vitamin K, a trend that coincides with a growing wave of mistrust toward vaccines and other newborn interventions.

Two studies published last week were the first to show that bleeding rates in US infants have increased along with rising refusals of vitamin K shots.

Newborns do not produce enough vitamin K, a critical nutrient for blood clotting, and injections at birth have been standard for over 60 years. As a result, the US Centers for Disease Control and Prevention does not record refusal figures or resulting bleeding cases.

Vitamin K refusals have been steadily increasing since the COVID-19 pandemic but have accelerated further under Health Secretary Robert F. Kennedy Jr., who spent decades raising doubts about vaccines before taking office. He has since removed six childhood vaccines from recommended schedules, though the changes remain paused by legal action. Health experts warn these shifting messages have deepened parental skepticism regarding basic newborn care, including vitamin K.

A US Department of Health and Human Services spokesperson confirmed the CDC still advises newborn vitamin K injections, but declined to state whether the agency will track refusal rates or bleeding incidents.

A JAMA study published last December by Dr. Kristan Scott and Children’s Hospital of Philadelphia researchers revealed that over 5% of US infants skipped vitamin K in 2024, a 77% surge since 2017.

The latest findings in JAMA and JAMA Pediatrics indicate refusal rates continue to climb, establishing a clearer link between declining uptake of the vital nutrient and an increase in bleeding incidents.

While the studies do not prove direct cause, the sharp rise in bleeding alongside declining vitamin K administration is significant, said Dr. Steven Woolf, an epidemiologist at Virginia Commonwealth University whose work appeared in JAMA Pediatrics.

Providing vitamin K shots at birth has been standard practice since 1961.

“Now we’re stepping away from that and we’re seeing the consequences,” he said.

Vitamin K refusals continue to climb

Woolf’s team analyzed records for 11 million infants six months and younger from 2017 to 2025. Over that timeframe, newborn vitamin K administration dropped from 97.7% to 95%, while deficiency-related bleeding nearly quadrupled, displaying accelerating growth.

Out of more than 11 million births, researchers identified 5,217 total bleeding cases during the multi-year study.

“The rate in 2025 was approximately double what it was in 2024,” Woolf said.

The authors observed that the 2025 peak aligns with fading public trust in healthcare following COVID-19, rising vaccine hesitancy, and broader doubts regarding early infant care.

An analysis for Reuters of over 1 million national births by health data firm Truveta showed vitamin K refusals picked up dramatically in early 2026, rising by more than 57% between January and June.

In Scott’s updated study in JAMA, researchers evaluated medical records from over 5.2 million US infants born between 2017 and 2025.

The proportion of infants missing vitamin K more than doubled from 3.1% in 2017 to 6.8% in 2025, climbing further from the 5.1% refusal rate seen at the end of 2024.

Infants who did not receive the injection had a 47% higher risk of bleeding during their first six months compared to those who did.

They also faced more than double the risk of brain bleeding within six months, and death linked to bleeding diagnoses during their post-birth hospital stay.

Researchers calculated that for every 114 newborns missing a vitamin K dose at birth, one additional bleeding incident occurs.

In June, Democratic Representative Kim Schrier of Washington and US Senator Angela Alsobrooks of Maryland called on the CDC to track bleeding cases.

Dr. Elizabeth Wolf, a Children’s Hospital of Richmond pediatrician who led the VCU study, said the findings highlight the need for clear public health messaging on vitamin K.

“Similar to the recent measles outbreaks, we are seeing the real-world implications of growing mistrust of doctors and public health professionals,” she said.