Why Do Newborns Need a Vitamin K Shot?

Doctors recommend that all newborns get a dose of vitamin K at birth. Babies aren't born with enough of this important vitamin, which is needed for blood to clot normally.

Without getting vitamin K at birth, babies can develop a dangerous bleeding problem called vitamin K deficient bleeding (VKDB). VKDB can cause bleeding in nearly every organ of the body, and can be fatal. Many babies with VKDB have bleeding in the brain that leads to brain damage. Babies with VKDB need intensive care, and many tests and treatments.

VKDB can happen over the first 6 months of life. That's because most of the vitamin K the body makes comes from the foods we eat and the healthy bacteria in our intestines. Until they start eating solid food at about 6 months of age, babies don't have enough naturally produced vitamin K. And nursing moms don't pass enough vitamin K in their breast milk to protect their babies from VKDB.

You may have seen or heard comments from parents who don't want their baby to get the shot. This is because a small study in the early 1990s suggested a link between the vitamin K shot and cancer. Larger studies since then have found no connection between vitamin K and cancer. But the outdated information can still be found online.

Some European countries let families choose an oral form of vitamin K. But this is far less effective than the shot at preventing bleeding, especially in the brain. Oral vitamin K is not available for newborns in the United States.

No parent enjoys the thought of their little one getting a shot. But a single injection of vitamin K can protect a baby from a serious, even deadly preventable bleeding problem. The Centers for Disease Control and Prevention (CDC) has more info about the vitamin K injection and VKDB.

If you have questions about your baby’s vitamin K shot, talk with your doctor.