U.S. Infant Vitamin K Bleeding Rises 347%

A review of health records from more than 11 million U.S. infants found that vitamin K shot coverage fell from 97.7% in 2017 to 95% in 2025, while diagnoses of vitamin K deficiency bleeding rose sharply. The rate of bleeding diagnoses increased from 24 to 107.4 per 100,000 infants, with most cases identified in the first week of life. A separate study of more than 5.2 million infants found that those who did not receive the shot had a higher risk of bleeding overall and more than twice the risk of bleeding in or around the brain. Because the studies are observational, they show an association rather than proving that declining vaccination caused every increase; researchers say newborns’ naturally low vitamin K levels make the injection an important preventive measure.