Why does my newborn need a vitamin K shot?

Vitamin K deficiency bleeding recently made the news when four cases of late bleeding were reported in healthy newborns in Nashville, Tenn. All parents had declined vitamin K, and their infants were reported to be developing normally until sudden bleeding occurred between 6 and 15 weeks. 

During my first year as a pediatric resident, I had the opportunity to work in the OHSU Mother-Baby Unit. It was fun and incredibly fulfilling to be the first medical provider for brand new babies and their parents. It was also an excellent time to review many of the current practices surrounding newborn care, including the routine vitamin K shot. I was asked to review what we know about vitamin K shots versus oral vitamin K and to share what I learned.

Why does my baby require vitamin K?

All babies are born with low levels of vitamin K, an important factor in helping a baby’s blood clot. We give all healthy newborns a vitamin K shot shortly after delivery to prevent a type of bleeding called Vitamin K deficiency bleeding (VKDB), formally known as hemorrhagic disease of the newborn. VKDB can range from bruising of the skin to bleeding inside the baby’s brain, and can occur from birth to months later.

Fortunately, there’s a simple and effective solution that has been recommended by the American Academy of Pediatrics since 1961 — a vitamin K shot at birth.

A shot versus oral medication?

In multiple scientific studies, the vitamin K shot has proved effective in preventing both early and late forms of bleeding. We administer vitamin K via injection because we don’t know enough about oral vitamin K to recommend its routine use.

Several countries have studied oral use, and early evidence shows a one-time oral dose to be less effective than the shot in preventing bleeding. That said, there are several ongoing international scientific studies evaluating the effectiveness of various oral vitamin K treatments given over several weeks. Many of these studies show that oral vitamin K may protect against Vitamin K deficiency bleeding, but not as effectively as giving the shot.

Additionally, the vitamin K oral formulations in the international studies are different than oral formulations available in the United States. Therefore, it is difficult to say if the United States would have similar results.

Unregulated vitamin K supplements not recommended

We do not recommend giving your baby vitamin K from a source not approved by the FDA. The FDA does not regulate vitamin supplements purchased over the counter and there is no way to tell if the dose is too little or too much.

In summary, we recommend the vitamin K shot to prevent Vitamin K deficiency bleeding, because we know it is effective. Right now, even with international studies on oral vitamin K, we just don’t know enough to recommend its use. We encourage moms-to-be to talk to their provider and their baby’s provider before delivery about vitamin K. They can provide more resources.

This post originally was written by Dr. Carrie Phillipi and updated by Dr. Allison Empey.

Allison Empey, M.D.
First-year Resident in Pediatrics

Carrie Phillipi, M.D., Ph.D.
Associate Professor of Pediatrics, OHSU Doernbecher Children’s Hospital
Director, OHSU Mother-Baby Unit 

To learn more about Vitamin K