The Vitamin K Shot: One Small Step That Protects Your Newborn

Preparing for a new baby comes with a lot of information and many decisions. One recommendation you will hear about after delivery is the vitamin K shot, which is routinely given to newborns shortly after birth.

You may have questions about why your baby needs vitamin K or whether the shot is necessary. Understanding what vitamin K does and why babies are born with low levels can help you feel more confident about this part of your baby's care.

What is vitamin K?

Vitamin K is a nutrient that helps our blood clot normally. Blood clotting is the body's natural way of stopping bleeding after an injury.

Older children and adults get vitamin K from foods such as leafy green vegetables, and bacteria in the digestive system also help produce vitamin K.

Why do newborns need vitamin K?

All babies are born with very low levels of vitamin K. This happens for a few reasons:

• Only a small amount of vitamin K passes from parent to baby during pregnancy.
• A newborn's digestive system does not yet have enough of the bacteria that help produce vitamin K.
• Breast milk naturally contains only small amounts of vitamin K.

Because of this, newborns do not have enough vitamin K to protect them from certain types of bleeding on their own.

What can happen without enough vitamin K?

Babies who do not have enough vitamin K are at risk for vitamin K deficiency bleeding (VKDB). VKDB can occur from birth through the first 6 months of life.

Some bleeding may happen inside the body where it cannot easily be seen. Late VKDB, which most often occurs between 2 weeks and 6 months of age, is particularly concerning because it can happen without warning. Bleeding may occur in the intestines or brain and can lead to serious complications.

Signs of possible bleeding

Seek medical care right away if your baby has:

• Unusual bruising
• Bleeding from the belly button, nose, or circumcision site
• Blood in their stool or vomit
• Unusual sleepiness or irritability
• Repeated vomiting
• Seizures

Some babies with VKDB do not have noticeable symptoms before a serious bleed occurs, which is why prevention is so important.

How does the vitamin K shot protect my baby?

A single vitamin K shot is given in the baby's thigh shortly after birth. The injection provides enough vitamin K to help protect your baby during the first several months of life, while their vitamin K levels naturally increase.

Babies who do not receive the vitamin K shot are significantly more likely to develop late VKDB. With the recommended injection, late VKDB is extremely rare.

Is the vitamin K shot safe?

The vitamin K shot has been routinely recommended for newborns for decades and has a well-established safety record.

Most babies have no problems after receiving it. Some may experience brief discomfort, redness, or a small bruise where the shot was given. Serious reactions are very rare.

Common questions about vitamin K

Is vitamin K a vaccine?

No. Vitamin K is a vitamin, not a vaccine. The injection simply provides your baby with vitamin K during a time when they naturally have very little of it.

If low vitamin K is normal in newborns, why does it need to be treated?

It is normal for babies to be born with low vitamin K, but those low levels also leave them vulnerable to serious bleeding. The vitamin K shot provides protection until babies are able to get and produce more vitamin K on their own.

Can my baby get enough vitamin K from breast milk?

Breast milk provides excellent nutrition for babies, but it naturally contains only small amounts of vitamin K. Breastfeeding alone does not provide enough vitamin K to prevent VKDB.

Can we use oral vitamin K instead?

Oral vitamin K does not provide the same reliable protection as the injection and requires multiple doses. There is currently no FDA-approved oral vitamin K product for preventing VKDB in newborns in the United States. For these reasons, the vitamin K injection is the recommended way to protect newborns.

Does the vitamin K shot cause cancer?

No. A small study published in the early 1990s raised concern about a possible connection between vitamin K injections and childhood cancer. Larger studies conducted since then have not found an association.

What if I have concerns about the vitamin K shot?

It is normal to have questions about medications and treatments recommended for your newborn. Your birth care team and pediatrician can talk with you about the benefits and risks and answer questions before your baby arrives.

The vitamin K shot is typically given shortly after birth. Parents can often hold, breastfeed, or have skin-to-skin contact with their baby to provide comfort when the injection is given.

If you are considering declining vitamin K, talk with your care team before delivery so you understand the risk of VKDB and what to watch for. Because serious bleeding can occur without warning, watching for symptoms does not provide the same protection as preventing VKDB with vitamin K.

If your baby does not receive vitamin K at birth, be sure to tell any health care provider caring for your baby during their first 6 months of life.

We're here to help

There is a lot to learn as you prepare to welcome a new baby, and we want you to feel comfortable asking questions about your baby's care. Talk with your birth care team or your Allegro pediatrician if you would like to learn more about vitamin K before delivery.

Once your baby is home, Allegro Pediatrics' 24-Hour Nurse Advice Line is available whenever you have questions or concerns about your baby's health.