By Brittany Grider, MD

Pediatricians consider medications given to newborn babies very carefully. There are generally plenty of safety data and studies evaluating if the benefits of a medication outweigh the potential harms. If we are encouraging you to give a medication to your baby, it’s because we feel that it is potentially lifesaving. 

One medication recommended for all newborns is Vitamin K. Vitamin K (phytonadione) is a fat-soluble vitamin that is necessary for blood to clot. We also need this vitamin in our bodies to stop bleeding from cuts and bruises. 

Vitamin K does not cross the placenta and is poorly excreted in breast milk. Also, due to differences in the gut microbiome in babies, it is poorly absorbed when we try to supplement it by mouth. The only way to give it to babies in the United States is by a one-time injection when they are newborns. 

Vitamin K deficiency is not just an issue immediately after birth —babies who do not receive Vitamin K remain deficient until they are at least six months old.

Pediatricians strongly recommend giving Vitamin K to newborns because of the risk for Hemorrhagic Disease of the Newborn, also called Vitamin K Deficiency Bleeding (VKDB). A hemorrhage is uncontrolled bleeding somewhere in the body. In newborns, hemorrhagic bleeding can occur in the belly, bladder, bowels, or brain. The bleeding can be severe and life-threatening, and brain bleeds can cause seizures and permanent disability. 

The only interventions for Hemorrhagic Disease of the Newborn are emergency blood transfusions and replacing the Vitamin K. These interventions, however, may not be enough to save a patient with bleeding. 

Vitamin K is safe, with no known toxicity, and its impact is huge. A one-time injection of this vitamin can protect babies from permanent disability or death for the first six months of life, which makes it quite special and potentially life-changing.