What is Vitamin K deficiency bleeding, and why does it occur in newborns? Here's what the new study found

The researchers from Virginia Commonwealth University have found a 347% increase in the number of infants suffering from vitamin K Deficiency Bleeding (VKDB) between 2017 and 2025 in a study. The research was published in JAMA Pediatrics after looking at the medical records of 11 million infants in the US. The researchers found that more parents were refusing to give their newborns vitamin K injections. Vitamin K helps with blood clotting and newborns have low levels of this vitamin. The bleeding can occur if they have a deficiency causing complications.

What is Vitamin K Deficiency Bleeding?

Vitamin K Deficiency Bleeding (VKDB) is also known as haemorrhagic disease of the newborn. This is a bleeding disorder caused in babies when they don't have enough vitamin K to help their blood to clot.


Newborns have low levels of vitamin K due to low amounts being transferred across the placenta during pregnancy, low amounts in breast milk and not having enough gut bacteria to create vitamin K initially. The newborns have received vitamin K injections to prevent this since 1961.

What did the new study find?

Researchers from Virginia Commonwealth University looked at the medical records of 11 million infants between 2017 and 2025. This was published in JAMA Pediatrics.

The research found:

• The percentage of newborns receiving vitamin K injections dropped from 97.7% to 95%.
• The number of cases of vitamin K deficiency (VKD) increased by 216%.
• The number of cases of vitamin K Deficiency Bleeding (VKDB) increased by 347%.
• Around 7% of babies with vitamin K deficiency and 2% of babies with VKDB had bleeding in or around their brain.

Lead author of the study is Dr Elizabeth Wolf. She is a paediatrician at Children’s Hospital of Richmond at VCU. Wolf said the researchers wanted to understand what the impact of more parents refusing vitamin K injections was. "We saw an increase in vitamin K deficiency and bleeding cases," she said.

She added that it was similar to measles outbreaks and that less confidence in doctors and public health professionals could have an impact on children.