What you need to know
- Vitamin K helps our blood clot. Babies aren’t born with enough vitamin K, which puts them at risk for life-threatening bleeding and strokes.
- Newborns in the U.S. have routinely received a vitamin K shot since the 1960s. The one-time injection significantly reduces the risk of vitamin K deficiency bleeding, or VKDB.
- Decades of research show that the vitamin K shot is safe.
A vitamin K shot has been given to newborns in the U.S. since the 1960s to protect them from life-threatening bleeding and strokes. The one-time injection is safe and saves lives. However, parents in the U.S. have been increasingly rejecting it for their infants. According to a recent analysis, the percentage of babies who didn’t receive the shot increased from 2.92 percent in 2017 to 5.18 percent in 2024.
Experts say some parents have refused the injection because of false claims about the shot. Despite several myths circulating online, the vitamin K shot is not a vaccine, research has shown it does not cause cancer, and its ingredients are safe.
“Vitamin K is extremely safe and has been used for multiple decades to protect [newborns],” Dr. Tina Tan, professor of pediatrics at the Northwestern University Feinberg School of Medicine, tells Public Good News. “It is important that parents understand the serious risk that the newborn is in and accept the vitamin K injection.”
Read on to learn more about the vitamin K shot: what it is, why babies need it, and more.
Why do babies need a vitamin K shot as soon as they’re born?
Vitamin K helps our blood clot, which means it helps stop bleeding and prevent uncontrolled bleeding. However, babies aren’t born with enough vitamin K because it doesn’t easily transfer through the placenta during pregnancy.
Additionally, a newborn’s intestines are still developing, so they can’t yet produce enough vitamin K on their own. (They start producing it when they begin to eat solid foods at around 6 months.) “[Newborn babies] cannot produce their own vitamin K unlike older infants, children, and adults who have gut bacteria that can use food intake to produce vitamin K,” Tan explains.
Because of this, babies who don’t receive the vitamin K shot are at risk of developing vitamin K deficiency bleeding (VKDB), a serious condition that can cause bleeding in the body or brain and may be fatal. VKDB can affect babies up to 6 months of age and may cause long-term brain issues.
What are the signs of VKDB?
According to the American Academy of Pediatrics, there often aren’t any warning signs of VKDB. However, babies with the condition may develop symptoms such as:
- Bleeding from the nose or umbilical cord
- Vomiting blood
- Pale skin or gums
- Bruising easily, especially on the face or head
- Yellow tint in the eyes (jaundice)
- Seizures
- Irritability
- Blood in the stool
- Unusual sleepiness
If you notice any signs of uncontrolled bleeding in your baby, seek emergency medical care right away.
Is the vitamin K shot safe?
Yes. Decades of research show that the vitamin K shot is very safe.
“In my over a decade of practice taking care of newborns, I have never seen a complication from the injection,” Dr. Jaspreet Loyal, medical director of inpatient pediatrics and associate professor of pediatrics at Yale Medicine, tells PGN.
Vitamin K is the main ingredient in the shot. Once a baby receives the injection, the vitamin is stored in the liver and released gradually over time until the body can produce enough on its own.
Loyal adds that if you have any questions about the shot’s safety, “your pediatrician is always a good source of information and guidance.”
What about oral vitamin K options?
While oral vitamin K is used in some European countries, there is no oral option approved by the Food and Drug Administration in the U.S. Loyal explains that studies have shown oral vitamin K is not as effective as the injection. “With oral vitamin K, there are cases of VKDB, [while] with the one-time injection, this risk is [virtually] zero,” Loyal says.
The injection reduces late-onset VKDB, which occurs one week to six months after birth, by 98 percent. Additionally, infants who don’t receive the shot at birth are 81 times more likely to develop late-onset VKDB than those who do.
If you have any other questions about the vitamin K shot, talk to your health care provider.