As I entered her room, Sally’s new baby was sleeping on her chest. She had given birth 3 hours ago and had just come to the postpartum unit where I was on duty as the newborn hospitalist for the day. My job was to take care of Sally’s new baby during her first few days of life. As I was reviewing her history and her delivery record, I noticed that Sally had declined the vitamin K injection. When I questioned her, she politely told me that she had done research and concluded that the vitamin K prophylaxis was not necessary and the shot had too many side effects.
Therefore, she declined to give consent for its administration to her new baby.
Throughout my time as a newborn hospital pediatrician, I had a similar discussion with many new parents. More and more families were declining the vitamin K prophylaxis at birth. Their reasoning for vitamin K refusal was varied. Many would tell me that they had read that there is an increased risk of childhood cancer after getting the injection. Others would tell me that they were refusing all vaccines, including the vitamin K one.
In this article we will understand what vitamin K is and why vitamin k for breastfed babies is especially important. We will also look at the myths surrounding the administration of injected vitamin K as well as understand the potential consequences of vitamin K refusal.
What is Vitamin K?
Vitamin K is a fat soluble vitamin that has two different active forms in the body.
- Vitamin K1 (also known as phylloquinone): This type of Vitamin K mainly comes from eating leafy green vegetables and other cruciferous vegetables.
- Vitamin K2 (also known as menaquinone)- This type of Vitamin K comes from a dietary source of fermented foods. Intestinal bacteria also create this form of vitamin K in the gut.
The main role of vitamin K in the body is as an essential component of the clotting cascade. It is imperative for the synthesis of many clotting factors including factors II, VII, IX, X as well as activation of anticoagulants C,S and Z. Additionally, vitamin K is necessary for cardiovascular health as well as bone metabolism in the human body.
Why is vitamin K for breastfed babies so important?
Vitamin K prophylaxis is important for many reasons. Without this injection, newborns are at risk for vitamin K deficiency bleeding.
First, infants are born with very low levels of vitamin k in their bodies. This is mainly due to the vitamin’s inability to cross the placenta during pregnancy. Researchers speculate that the reason for this is that a newborn’s circulation does not have the correct amount of lipoprotein for transporting this vitamin across the placenta.
A second reason for low vitamin K in babies is due to the lack of a certain type of bacteria in their gut. Babies seem to be lacking this type of bacteria early on. Newborns become colonized with the good bacteria that comes from their mother’s body shortly after birth. Additionally, breast milk also provides and feeds the helpful bacteria in the baby’s gut.
Lastly, breastfed babies do not get enough Vitamin K from their diet. Breast milk is low in vitamin K and therefore infants don’t get enough to prevent vitamin K deficiency bleeding. On the other hand, infant formula is fortified with many vitamins, including vitamin K. However, newborns don’t take in enough volume of either breast milk or formula in the early hours after birth to make a difference in their vitamin K levels. Without the vitamin K injection, this puts them at risk for vitamin K deficiency bleeding.
Are oral doses an appropriate substitute for a vitamin K injection?
You can find a dose for oral vitamin K on the internet, but there is no FDA approved dose in this country. In addition, oral doses are inconsistently absorbed by a newborn’s immature gut. In countries where oral vitamin K is given due to lack of intramuscular doses, this form does not consistently prevent late vitamin K deficiency bleeding.
On the other hand, when we inject vitamin K into a large muscle, it provides a consistent dose to the baby over time. Initially, the liver stores vitamin K. Subsequently, the liver releases the vitamin slowly over time. This gives the newborn enough Vitamin K to prevent bleeding.
This dose of vitamin K carries the baby through until about 6 months of age. This is when they can begin consuming vitamin K in their diet through solid foods.
What happens to babies who don’t get vitamin K?
In the setting of vitamin k deficiency, newborn babies have a risk of serious bleeding. We call this type of bleeding vitamin K deficiency bleeding (it used to be called hemorrhagic disease of the newborn).
VKDB is divided into three different categories depending on how old the baby is when the bleeding occurs.
Early onset vitamin K deficiency bleeding: Occurs within the first 24 hours of life. Consists of severe bleeding in the newborn’s gut, chest or brain. Babies whose mothers are on vitamin K blocking medications such as warfarin, seizure medications or TB medications are at higher risk for early bleeding (without prophylaxis).
Classic vitamin K deficiency bleeding: Happens within the first week of life. Consists of oozing bleeding of umbilicus, circumcision, needle poke sites, or GI tract
Late onset vitamin K deficiency bleeding: Can happen within the first 6 months of life. Potentially results in severe intracranial bleeding. This form of bleeding is extremely rare, but results in death or significant morbidity 50% of the time (most often due to brain damage).Vitamin K prophylaxis at birth prevents this type of bleed almost 100% of the time. (prophylaxis = attempt to prevent disease)
While the overall risk of vitamin K deficiency bleeding is relatively low for newborns who do not receive the vitamin K injection, the effects of bleeding are potentially devastating.
As a part of routine newborn care, all newborns receive an injection of vitamin K within 6 hours of birth. The dose of vitamin K is 1 mg.
If breast milk is perfect, why is it low in Vitamin K?
Human milk contains vitamin K. However, levels in breast milk are not high enough to prevent VKDB in breastfed babies. As we talked about earlier, newborn infants do not have adequate stores or amounts of vitamin K in their system at birth. This combined with low levels of vitamin K in breast milk leaves the breastfed infant vulnerable to vitamin K deficiency bleeding without prophylactic vitamin K.
However, there is research that shows how it is possible to increase vitamin K levels in breast milk. Just like we have seen with vitamin D supplementation of mothers, a breastfeeding mom can take a vitamin K supplement to increase the levels of these vitamins in her milk.
In 1997, Greer, et al conducted a small study that showed how to increase vitamin K levels in mother’s milk. If a mother took a 2.5 mg dose of vitamin K daily, her breast milk vitamin K levels would increase. There are many limits to this study, but it shows us that it is possible to increase vitamin K levels in breast milk.
Nevertheless, as we saw in our discussion of vitamin K levels in formula, we theorize that babies do not take in enough breast milk in the early hours after birth to increase their vitamin K levels. Or at least to increase their vitamin K levels enough to prevent early onset vitamin K deficiency bleeding.
We also don’t have any research that shows whether breast milk levels of vitamin K correlate with a baby’s blood level or whether supplementing breastfeeding mothers with vitamin K will prevent bleeding in the newborn. Likely, no scientist would ever do this type of study. It would be unethical to withhold the vitamin K injection in order to study whether a baby’s levels increased with breast milk levels.
What are the myths surrounding vitamin K prophylaxis for newborns?
Parents cite many reasons for refusal of the vitamin K injection at birth. Most of the time, it is due to an untruth that they found on the internet.
Link to Childhood Cancer
In the early 1990s a group of doctors was studying pregnancy and maternity practices in the UK. In their studies, they thought that they found a link between vitamin K injection and childhood cancer (leukemia).
However, since that time, there have been many other studies that have proven the safety of this injectable vitamin, and there is no association with increased cancer risk.
In addition, this neonatal vitamin has been given safely and routinely to babies since 1961.
Vaccine refusal
As part of routine newborn care in the United States, newborns go through screenings and preventive procedures during their short stay in the hospital.
Within the first 48 hours of life, babies receive:
- One dose of intramuscular vitamin K to prevent bleeding
- Eye ointment to prevent blindness from certain maternal infections
- The first dose of Hepatitis B vaccine via intramuscular injection
In addition, they also undergo several screenings before they leave the hospital. As a part of this whirlwind of activity, it is completely understandable why some parents could think that the vitamin K injection is a vaccine. However, it is not a vaccine used to prevent disease. It is an injectable vitamin that we use to prevent bleeding in the newborn period.
The ingredients are concerning
While it is definitely important to know what you are putting in your newborn’s body, the ingredient list for the vitamin K injection is readily available on the internet.
Here is a screen shot of the ingredients found on the package insert for the most widely used form of injected vitamin K used by hospitals.
Phytonadione is also known as Vitamin K1. The rest of the ingredients are used for preserving and buffering the solution so that it stays in liquid form. Thankfully, these compounds are safe and have been used in medications for many years.
However, if you are still concerned, there is a preservative free version of the injection as well.
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© 127 Pediatrics, May 2024
This article is for information purposes only. Please consult your personal physician for medical advice.
Dr. Andrea Wadley is a board certified pediatrician and breastfeeding medicine doctor. She owns and operates 127 Pediatrics, based in Colleyville, Texas.
