An increasing number of parents are declining vitamin K injections for their newborns—a trend that researchers say could put infants at significantly higher risk of life‑threatening brain bleeds and long‑term disabilities, according to a new study.
The findings will be presented at the American Academy of Neurology’s 78th Annual Meeting, which is being held from April 18–22, 2026 in Chicago.
Vitamin K is an essential nutrient that helps the blood clot, but newborns are naturally born with low levels.
A vitamin K shot shortly after birth can prevent vitamin K deficiency bleeding, a rare but dangerous condition that can trigger intracerebral hemorrhage, a type of stroke caused by a ruptured blood vessel in the brain.
The American Academy of Neurology stresses that the injection is a supplement—not a vaccine.
While overall refusal remains uncommon in the U.S., typically below 1 percent, the review found the rate has been rising. In Minnesota, refusals increased from 0.9 percent in 2015 to 1.6 percent in 2019.
In California, Connecticut, and Iowa, rates ranged from 0.2 percent to 1.3 percent, with more than half of hospital workers across those states reporting they had noticed more parents declining the shot.
“Vitamin K at birth is safe and effective, and while refusal is still uncommon with rates in the United States remaining under 1 per cent in most hospitals, our review found in recent years, there have been increases in parents refusing this supplement for their newborns,” said study author Dr. Kate Semidey of the Florida International University in Miami.
“This trend is concerning because our review also found that babies who do not get the vitamin K injection are 81 times more likely to develop vitamin K deficiency bleeding.”
The review examined 25 studies spanning two decades of global data. Internationally, refusal rates ranged from 1 to 3 percent in Canada, New Zealand and Scotland, and even exceeded 30 percent in select birthing centers.
Among reported cases of babies who experienced vitamin K deficiency bleeding, researchers found approximately 14 percent died. About 40 percent had lasting neurological disabilities—such as seizures, motor issues or cognitive impairment—and around 63 percent had brain bleeds.
The research also suggests refusal of vitamin K may be part of a broader pattern of health care hesitancy. In the U.S., parents declining the injection were 90 times more likely to also refuse the hepatitis B vaccine and protective eye medication given at birth.
In Canada, they were 15 times more likely to have an unvaccinated child at 15 months, and in New Zealand, 14 times more likely.
Parents commonly cited concerns about pain, preservatives or inaccurate information found online.
“Our findings point to an urgent need for health care professionals to provide prenatal counseling to parents to ensure they understand that vitamin K can dramatically reduce preventable brain injury and its lifelong impact,” Semidey said.
The authors note the limitation that the analysis relies on previously published research and does not track infants’ outcomes over time.
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