Submission + - Infant Bleeding Surged as Parents Rejected Vitamin K Shots, Studies Find (nytimes.com) 2
For decades, the American Academy of Pediatrics has recommended that every newborn receive an injection of vitamin K, which helps blood clot and can protect against sudden and catastrophic bleeding that can occur even in otherwise healthy babies. The injection is not a vaccine, but as mistrust in medicine has grown and as Health Secretary Robert F. Kennedy Jr. and other prominent health figures have cast doubt on the importance of childhood vaccinations, more parents have started forgoing it.
With fewer babies getting these injections, doctors had already begun to see more infants with serious hemorrhages. The new studies, published Thursday in the journals JAMA and JAMA Pediatrics, provide some of the first concrete data on this pattern. One found an especially sharp increase from 2024 to 2025, with cases of vitamin K deficiency bleeding roughly doubling in that time.
The JAMA study looked at more than five million infants. In 2017, 3.1 percent of these newborns went without a vitamin K shot; by 2025, it was 6.8 percent. The infants who had not received the shot had significantly higher rates of bleeding in their first six months, including more than double the risk of brain bleeds, which are especially deadly: 33 brain bleeds per 10,000 births, compared with 13.2 per 10,000 for babies who received vitamin K.
The JAMA Pediatrics study, on which Dr. Woolf was a co-author, looked at more than 11 million infants and found similarly that the rate of infants going without vitamin K more than doubled from 2017 to 2025. The overall rate of vitamin K deficiency bleeding rose nearly 350 percent, to 107.4 cases per 100,000.
The vitamin K injection is very safe, but more parents started declining it in the 2010s, citing, among other things, a belief that the shot was unnatural or unnecessary.
Dr. Elizabeth Wolf, an author of the JAMA Pediatrics study and an associate professor of pediatrics at Virginia Commonwealth University, said she hoped the results would break through to parents who may not realize the severity of the risk of going without vitamin K.