Nutrition • Mar 29, 2010

Does My Newborn Need Vitamin K?

I see many infants in the first few hours of life, and I know (as both a pediatrician and a mother!) that bonding and quality time are essential to new families during this early time.  Unfortunately, there are some things that medical professionals need to do during this time, and understanding the importance behind our involvement may help to alleviate your concerns about whether they are necessary.  For example, sometimes new parents wonder if it is necessary to give their newborn a Vitamin K shot.  The short answer is “yes.”  If you would like a more detailed explanation of why, read on…

First, here is a little background about Vitamin K and why it is important. Vitamins are organic substances needed by the human body for various metabolic pathways. The human body cannot make vitamins, so we must ingest them.  In general, healthy people consuming a well-balanced diet can get all the vitamins they need from their diet, but there are certain exceptions.  The important exception we will focus on here is Vitamin K in the newborn.

Why is Vitamin K so important?  Among other things, it plays a crucial role in the coagulation pathways of the human body, which means it is necessary for blood clotting.  Specifically, it is a required cofactor in the activation of factors VII, IX, X, and prothrombin, which are needed to activate platelets to stick together and form a clot to stop bleeding.  Essentially, without Vitamin K, your body cannot effectively clot its blood.

So why is Vitamin K, more so than other vitamins, a concern in the newborn period?  Newborn Vitamin K deficiency is common because of many factors.  For one, Vitamin K absorption and activation require the liver, and newborns have immature livers, meaning that they are not as efficient at absorbing and activating Vitamin K.  Secondly, Vitamin K is not transferred well across the placenta, and it is also not present in high amounts in breast milk. In addition, newborns lack the healthy intestinal bacteria (or gut flora), which produce Vitamin K in the intestines.

So what happens if a newborn does not receive Vitamin K supplement?  As many parents know, the majority of these babies will suffer no untoward consequences and end up just fine.  However, a small subset of children, about 2% of those not given Vitamin K, will develop hemorrhagic disease of the newborn, or Vitamin K deficient bleeding (VKDB).  This disorder typically occurs in the first week of life, but can happen weeks or even months after birth. It consists of bleeding from a number of sites because of a lack of Vitamin K.  Not only do these infants bleed from small wounds in the skin, but more seriously, they can bleed within the gastrointestinal tract and brain.  The disease is more common and more severe among un-supplemented children whose mothers were exposed to Coumadin, anti-seizure medications and certain antibiotics during pregnancy, but unfortunately, it can happen to other un-supplemented babies as well, and there is not a good way to predict which ones will be affected. 

Sometimes parents ask whether they can just wait to see if their baby develops the disease.  Unfortunately, the disease can be incredibly disabling and even fatal; and once it is diagnosed, it may be too late for life-saving therapies.  Another common question is whether it is possible to provide the Vitamin K without a shot (because of course no parent wants an unnecessary shot for their baby).  There is indeed an oral formulation, but it is less effective than the shot, and it is not approved for use in the United States.  Some breast-feeding mothers also question whether they could take supplements to increase the concentration in their breast-milk, but this method has not been proven to work.

For all these reasons, the American Academy of Pediatrics recommends universal treatment of all newborns in the United States with a Vitamin K shot shortly after birth.  While the risk is not large that any particular baby will develop this disease, the seriousness of the disease itself (combined with the low risk of the shot) is the reason for this recommendation.  2% may seem like a low number, but it is still 2 of every 100 babies born, and if your baby is one of them, it can be devastating.  So is it really worth taking the risk?  The good news is that the shot is usually given right after birth while the medical staff is warming and measuring the baby, and while mom is still finishing the delivery.  Other family is usually welcome to be with the baby (generally just across the room from mom) to comfort the baby during the shot.  If you have questions or concerns about how and when the shot will be given, or if you have further questions as to its necessity, please feel free to discuss these with your pediatrician or other care provider.