Why does my newborn need a vitamin K shot?

All babies are born with low levels of vitamin K, an important factor in helping a baby’s blood clot. That’s why we give all healthy newborns a vitamin K shot shortly after delivery. The shot helps prevent a type of bleeding called hemorrhagic disease of the newborn, which can range from bruising of the skin to bleeding inside the baby’s brain.

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 today 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 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.

We give the vitamin K dose in one shot, which may cause a brief pain reaction in the baby. Although the vitamin K shot is more effective than oral vitamin K, both forms are safe and well-tolerated. If a family chooses to give their baby oral vitamin K rather than the injection, we currently recommend giving the medication at birth, 1 week and 6 weeks of age.

Unregulated vitamin K supplements not recommended

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

We recommend moms-to-be talk to their provider and their baby’s provider before delivery about vitamin K. They can provide more resources.

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

“Controversies Concerning Vitamin K and the Newborn,” Pediatrics, American Academy of Pediatrics.
“Prevention of vitamin K deficiency bleeding: efficacy of different multiple dose schedules of vitamin K,” National Center for Biotechnology Information, National Institutes of Health.
“Prophylactic vitamin K for vitamin K deficiency bleeding in neonates,” Cochrane Database of Systematic Reviews.