Why Does My Newborn Baby Need a Vitamin K Shot? What Every Parent Should Know

Vitamin K written in colored letters

Why Does My Newborn Baby Need a Vitamin K Shot? What Every Parent Should Know

When newborns are in the hospital, they have a few key screening tests to make sure they’re off to a healthy start. Another critical part of newborn care is a vitamin K shot given shortly after birth.

Many families have questions and are even considering declining this safe, life-saving vitamin K injection, often due to misinformation spreading on social media sites.

Vitamin K is recommended for all newborn babies but if your baby is born prematurely or needs care in the Neonatal Intensive Care Unit (NICU), understanding the role of vitamin K in preventing bleeding becomes even more important. Annmarie Golioto, MD, Medical Director of the NICU at Connecticut Children’s, answers questions many parents are asking.

 

Vitamin K: A Lifeline for Newborns

Every baby is born with naturally low vitamin K levels. A single vitamin K shot shortly after birth gives babies immediate protection from bleeding during this very vulnerable time.  At birth, your baby is still developing the ability to make vitamin K, primarily from bacteria in the gut. 

Why do babies need vitamin K?

Every baby is born with very little vitamin K in their body because only a small amount passes on to them through the placenta. Vitamin K helps the body’s blood clot normally. Even small injuries can lead to serious bleeding when there is not enough Vitamin K in the body.

Adults and older kids get vitamin K from certain foods and from healthy bacteria that naturally live in the intestines and make vitamin K.  Newborn intestines don’t have the bacteria to produce vitamin K until after they are born and start eating, so it takes time to build up their own levels. 

Can my baby get enough vitamin K from my breast milk?

No. While breast milk has tremendous nutritional benefits, it does not have enough vitamin K alone to provide the amount that is needed.  The baby still relies on waiting for gut bacteria to make vitamin K if they do not receive the shot to increase their levels at birth.
 

Why is vitamin K especially important for babies in the NICU?

Babies in the NICU often have health challenges that make preventing bleeding even more important: 

  1. Preemies and sick babies have livers that are still learning.
    The liver has a role in helping with blood clotting to stop bleeding. If a baby is born too early or born critically ill, their liver is slow to do its job. This makes it very hard for their bodies to use the very small amount of vitamin K they have. 
     
  2. Feeding into the intestines doesn’t always happen right away.
    For a few different reasons, many babies in the NICU cannot have breastmilk or formula into their stomachs right away. They may get their nutrition from other sources  directly into their veins the first days or weeks of life. Healthy gut bacteria develop after feeding starts, and those bacteria help make vitamin K. Babies who cannot eat breastmilk or formula will have an extra delay in making their own vitamin K.
     
  3. NICU care can mean medical procedures or surgery.
    Babies in the NICU may need blood draws, heel pricks, IVs, central lines, and tubes in their bodies that can cause bleeding if their blood does not clot normally.  Surgeries may be needed and can result in extreme bleeding without Vitamin K.  Healthy blood clotting helps reduce the risk of excessive bleeding during these lifesaving procedures.
     
  4. Preventing brain bleeds is extremely important.
    One of the most serious complications of vitamin K deficiency is bleeding inside or around the brain. This can happen without warning and may cause permanent brain injury or even death. Preventing these bleeds that can change a baby’s life forever is one of the reasons vitamin K is considered such an important part of newborn care.  Premature infants with fragile blood vessels in their brains are even more at risk.

>>Related: What to expect during a NICU stay

 

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Alarmingly, there are no warning signs before a serious bleed. When the bleeding develops after one week of life about 50% of babies will present with brain bleeds from Vitamin K deficiency. Refusing the shot all together leaves a newborn 80 times more likely to develop late onset VKDB with approximately 15-20% mortality.

Annmarie Golioto, MD, IBCLC, FAAP, Medical Director, Neonatology,
Connecticut Children's

What is Vitamin K Deficiency Bleeding (VKDB)?

Vitamin K Deficiency Bleeding, or VKDB, happens when a baby doesn't have enough vitamin K to clot their blood. Bleeding can happen:

  • In the brain, causing a baby to stop breathing or have a seizure
  • In the intestines causing a baby to vomit blood or have blood in their stool
  • Oozing of blood from the umbilical cord
  • Skin bruising
  • After a procedures or surgeries 

Is the vitamin K shot safe for newborns?

Yes.

Since 1961, The American Academy of Pediatrics has recommended a single vitamin K injection for all newborns. It has been used safely in millions of babies worldwide and is still the most effective way to prevent VKDB.

Is vitamin K given orally just as effective as the injection?

There is no FDA approved oral vitamin K for newborns in the United States.  The American Academy of Pediatrics also states this is not recommended because giving vitamin K orally:

  • Requires multiple doses over days, weeks or months to remember
  • Has not been shown to protect babies as safely or as fast as the single injection at birth

I've seen conflicting information online about vitamin K. What should I believe?

You should believe your pediatrician or the NICU team as the experts. They can explain the evidence and answer your questions.  

In many aspects of life, social media often shares incomplete or inaccurate information. If you're ever unsure, please ask the professionals.

As pediatric experts 100% dedicated to kids, we don’t just recommend treatments. We help families understand why they're important and make informed decisions together.