Key facts
- The share of newborns not receiving a vitamin K shot rose to 6.8% in 2025 from 3.1% in 2017, a JAMA study found.
- Babies who missed the shot had a 47% higher risk of bleeding in their first six months, the JAMA study found.
- A JAMA Pediatrics study of 11 million infants found vitamin K deficiency bleeding nearly quadrupled between 2017 and 2025.
- The studies do not prove that refusals caused the bleeding increase, the report states.
Rates of life-threatening bleeding in US infants have risen since 2017 as more parents refuse protective vitamin K doses for newborns, according to two studies published on November 5 in JAMA and JAMA Pediatrics. The studies are the first to show that infant bleeding rates have increased alongside rising vitamin K refusals, Reuters reported.
Babies are not born with enough vitamin K, a nutrient that helps blood clot, and injections at birth have been standard for more than 60 years. The CDC does not track vitamin K refusal or bleeding rates. Refusals have risen since the COVID-19 pandemic and accelerated under Health Secretary Robert F. Kennedy Jr., who has dropped childhood recommendations for six vaccines; changes to the childhood vaccination schedule are on hold over a legal challenge.
A study in JAMA by Dr. Kristan Scott of the Children's Hospital of Philadelphia found that the share of newborns not receiving a vitamin K shot more than doubled to 6.8% in 2025 from 3.1% in 2017, and rose from 5.1% at the end of 2024. Babies who did not receive the shot had a 47% higher risk of bleeding within the first six months and more than twice the risk of brain bleeding, the authors found. They calculated that one additional bleeding event would occur for every 114 newborns who do not receive the shot.
Dr. Steven Woolf, an epidemiologist at Virginia Commonwealth University, and colleagues studied records from 11 million infants six months and younger between 2017 and 2025. The share of newborns receiving a vitamin K shot fell from 97.7% to 95%, while vitamin K deficiency bleeding nearly quadrupled and appeared to be accelerating. Of more than 11 million births, there were 5,217 bleeding events over the period. Woolf said the 2025 rate was approximately double the 2024 rate.
An analysis for Reuters of more than 1 million births by health data company Truveta found vitamin K refusals jumped more than 57% from January through June 2026. Dr. Elizabeth Wolf, a pediatrician at Children's Hospital of Richmond who led the VCU study, said the findings call for clear public health messages about vitamin K.