Infant Vitamin K Deficiency Diagnoses Climbed 216% As Shots Declined

Infant Bleeding Diagnoses Linked to Vitamin K Deficiency Climbed 347%

A routine newborn shot is losing a little ground, and a dangerous infant bleeding condition is gaining a lot. Between 2017 and 2025, the share of babies receiving the standard vitamin K injection slipped only slightly, from 97.7% to 95.0%. Over those same years, the rate of vitamin K-deficient bleeding diagnoses in infants rose 347%, and the rate of vitamin K deficiency diagnoses rose 216%, according to a new national study in JAMA Pediatrics.

Most infants diagnosed with either problem had no recorded vitamin K shot. Bleeding inside the skull is the gravest risk, and it can cause permanent brain damage, seizures, or death.

Authors of the study say the data raise concerns about parents refusing the injection, but the study cannot prove that refusals drove the rise. In their words, “association does not prove causality.”

Records From 11 Million Infants Show Vitamin K Shot Rates Dipped Slightly

Researchers in Richmond, Virginia, mined Cosmos, a large database of medical records from health systems that use the same record-keeping software, covering more than 2,300 hospitals and 50,000 outpatient care sites. Every infant in the database from birth to 6 months old who was born at 35 weeks of pregnancy or later and received care between January 2017 and December 2025 made the cut.

That added up to about 11 million infants, roughly 51% of them boys and 31% on public insurance. Billing and diagnosis codes in their records identified babies with vitamin K deficiency, bleeding caused by it, and bleeding inside the skull. Births in the database roughly doubled over the period, from about 787,000 in 2017 to about 1.6 million in 2025, so rates, not raw counts, give the fairer comparison.

Babies come into the world short on vitamin K, a nutrient the body needs to make several proteins that clot blood. Little of it crosses from mother to baby before birth, a newborn’s gut makes limited amounts, and breast milk is low in it too. Deficiency can show up within the first day of life, usually tied to medications the mother took, or in the first week as bruising or bleeding where the umbilical cord was attached. The late form, which strikes between 1 week and 6 months of age, carries a 30% to 60% risk of bleeding in the brain. Since 1961, the American Academy of Pediatrics has recommended a single injection for every newborn, and it cuts late vitamin K-deficient bleeding by 98%.

Most Infants Diagnosed With Vitamin K Deficiency Had No Recorded Shot

Across the nine years, 2,151 infants were diagnosed with vitamin K deficiency and 5,217 with vitamin K-deficient bleeding. Most diagnoses came in the first week of life, about 6 in 10 deficiency cases and nearly 9 in 10 bleeding cases. Bleeding diagnoses went from about 1 in 4,200 infants in 2017 to about 1 in 930 in 2025, and both conditions peaked in that final year.

Only about 4 in 10 infants with the deficiency, and about 2 in 10 with the bleeding condition, had received the injection. Bleeding inside the skull showed up in about 7% of deficiency cases and about 2% of bleeding cases, though the authors say brain bleeds may have been undercounted. The study did not track why any individual baby went without the shot, and because it relies on medical records, a missing entry does not always mean a missed shot.

Researchers also checked whether other known risk factors could explain the jump. Breastfeeding, a known risk factor, has changed little over the last decade, and health conditions that make absorbing the vitamin harder, such as cystic fibrosis, have declined or held steady. Those checks matter because a jump in bleeding could otherwise come from more breastfed babies or more babies with absorption problems rather than from fewer shots. Authors consider these explanations unlikely.

Authors Suggest an Oral Option if Vitamin K Shot Refusals Keep Rising

Authors note that the rise in diagnoses coincides with eroding trust in public health since the COVID-19 pandemic, growing vaccine hesitancy, and parental unease about procedures given to newborns. A Swedish study cited in the paper linked going without the shot to bleeding episodes in infancy.

Researchers write that, as with childhood immunizations, the shot “may be a victim of its own success,” because the bleeding has been rare for so long that many of today’s families may be largely unaware of its grave consequences.

Oral vitamin K is offered, either routinely or as an alternative to the injection, in France, Germany, the Netherlands, Switzerland, and Canada. It can be less effective at preventing the late form of the deficiency. Still, the authors write that offering it as a backup option may be warranted in the U.S. if rejection of the injection continues.

A shot that reaches about 95% of newborns sounds like a win, and it is. Yet the condition it was built to prevent is turning up more often in health records, which gives parents weighing the decision a good reason to talk it through with a pediatrician before the baby arrives.

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Disclaimer: This article summarizes a published research letter and is intended for general informational purposes only. It is not medical advice. Questions about a newborn’s care, including vitamin K, should be directed to a pediatrician or other qualified health professional.

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