What is the vitamin K shot? Why every newborn needs it

When welcoming a baby into the world, there are many decisions to make in a short amount of time. One of those decisions you must make is whether or not to give your child a vitamin K injection at birth. So, what is a vitamin K shot, and why is it important for newborns?

The vitamin K shot

What is the vitamin K shot? Why is it important? 

Vitamin K is essential for blood clotting. Newborns have very low levels of vitamin K naturally, which puts them at risk for vitamin K deficiency bleeding (VKDB), a rare but serious condition where infants cannot properly clot blood due to low vitamin K levels. 

This single shot protects your baby for months. 

When and how is vitamin K given?

One mg of intramuscular (shot) vitamin K1 is given to full-term babies that weigh more than 3.3 pounds within six hours of birth. For preterm infants that weigh less than 3.3 pounds, 0.3-0.5 mg of intramuscular vitamin K1 is given within six hours after birth. 

Is vitamin K safe?

Yes. Studies show no link between the intramuscular vitamin K shot and childhood cancers. The vitamin K shot also does not cause jaundice, a medical condition causing yellowing of the skin and eyes. Side effects of vitamin K injections in newborns may include temporary redness or soreness at the injection site. 

Vitamin K deficiency bleeding

What is vitamin K deficiency bleeding?

Vitamin K deficiency bleeding (VKDB) is a serious condition that can cause uncontrolled bleeding in babies. It can be life-threatening if it occurs inside the brain or organs. 

Without supplementation, VKDB can occur in 1 in 60-250 newborns. It can occur early (within 24 hours of birth), classic (within the first week of life), and late (between two weeks and six months of age). The most serious – late KVDB – occurs in 4-7 per 100,000 babies who do not receive vitamin K. 

Breast milk contains low vitamin K, so exclusively breastfed babies without supplementation are at the highest risk of late VKDB.

What are the warning signs of VKDB?

Signs of VKDB include unexplained bruising or bleeding in the umbilical cord, gums, and nose; blood in stool or vomit; and excessive sleepiness, irritability, or a bulging soft spot. Call your doctor if your baby has any of these symptoms.

Please note, some babies may show no warning signs. 

Learn more about VKDB from the Centers for Disease Control and Prevention here. 

Why do parents refuse the vitamin K shot?

What are some common misconceptions of the vitamin K shot?

There are many myths about the vitamin K shot that may deter parents from wanting their child to receive the vitamin K shot. 

One is that the vitamin K shot is a vaccine. The vitamin K shot is not a vaccine, but simply a shot giving vitamin K1 (phytonadione), which is a nutrient. It does not affect the immune system. Vaccines are a treatment given to build immunity, while a shot injects a substance into the body. 

Another is that the vitamin K shot contains harmful preservatives, but most hospitals use preservative-free formulations, which simply include vitamin K1, sterile water, and in some cases, a small amount of benzyl alcohol as a stabilizer. Here at The Valley Hospital, we only use preservative-free (alcohol-free) phytonadione injections for our infants.

Parents may also believe that simply using delayed cord clamping can give enough vitamin K; however, babies receive very little vitamin K from the placenta. 

What happens if parents decline the vitamin K shot?

By declining the vitamin K shot, your baby remains at risk of internal bleeding. The hospital may require a declination form acknowledging the risk.

Vitamin K shot alternatives 

Can delayed cord clamping or maternal diet replace the shot?

No. Very little vitamin K passes through the placenta or breast milk. Supplementation is still necessary. 

Is oral vitamin K more effective than the vitamin K shot?

No. It is less efficacious than a vitamin K shot. It's not approved in the United States. In some countries, oral vitamin K is being used where there is a proper system for home visits for four to six weeks, which is not available in the U.S. Studies done in those countries have still shown that babies are at an increased risk of late-onset vitamin K deficiency bleeding. So, we do not recommend oral vitamin K. It's not available in our hospital.

Vitamin K shot and circumcision 

While the vitamin K shot is necessary for all babies, it is especially necessary if parents elect for their child to undergo circumcision. The vitamin K shot has shown to significantly reduce bleeding risk in neonatal circumcision. Vitamin K will need to be administered before the circumcision.

The bottom line for parents

Vitamin K prevents a potentially fatal bleeding disorder. The intramuscular vitamin K shot is the safest and most effective way to protect your baby from a vitamin K deficiency disease. 

If you have any questions about the vitamin K shot, please speak to your pediatrician. To find a Valley pediatrician or to learn more about pediatric primary care at Valley, please visit ValleyHealth.com/PedsPrimaryCare.