Why newborns need a vitamin K shot

With ten tiny fingers and ten tiny toes, a newborn infant seems perfectly made. But the one thing a baby is not born with is enough vitamin K. For this reason, the American Academy of Pediatrics since 1961 has strongly recommended that all newborns receive a dose of vitamin K at birth. This has been the standard of care for infants since that time. However in the last few years, there has been a small, but alarming trend of parents who are opting to defer the injection at birth.

Vitamin K is a crucial vitamin that helps the body activate clotting factors, which can prevent bleeding. It does not pass in sufficient quantity to an infant during pregnancy, so every baby is born deficient. Most of the vitamin K we make in our bodies comes from the food we eat and from healthy bacteria in our intestines. Babies remain deficient for several months until they are eating solid food close to six months of age. Vitamin K is not passed to babies in breast milk in enough quantity to be protective, so breast fed babies are at the highest risk of having vitamin K deficient bleeding.

The soft, snuggly bodies of newborn babies also make them more likely to have bleeding. When babies do not receive vitamin K at birth, they are more likely to suffer a potentially fatal bleeding disorder called "vitamin K deficient bleeding" or VKDB. Their thinly-walled blood vessels and mobile joints make them more susceptible to spontaneous, life- threatening bleeding. The bleeding associated with vitamin K deficiency can occur any time after birth until six months of age. Symptoms can include bruising or bleeding in nearly every organ of the body, and nearly 50 percent of cases involve serious damage to the brain.

If vitamin K is so incredibly helpful at protecting infants, then why are people refusing the injection? A parent wants to do what is best for their child, but often information found on the internet can create confusion. A study was reported over 20 years ago that linked the vitamin K injection with childhood cancer. Multiple studies since then have found no connection at all between vitamin K and cancer.

Some families have recently sought alternate ways for their infants to receive vitamin K.  In several European countries, families can opt for an oral form of the vitamin. But studies have shown this treatment is not nearly as effective at preventing bleeding, especially bleeding in the brain. In the United States, an oral liquid form of vitamin K is not currently available for a physician to prescribe. An oral regimen of vitamin K is not supported by the American Academy of Pediatrics because it is not as effective.

Being a parent and making medical decisions for a child can feel like a daunting responsibility, especially in the first few weeks of a child's life. Miraculously, a simple injection of vitamin K given when an infant is first born is protective from the potential devastating side effects of vitamin K deficient bleeding. With one small injection, an infant gains a massive amount of protection from a preventable bleeding disorder. The U.S. Centers for Disease Control has more information about vitamin K deficiency bleeding.

Michelle Karten, MD, FAAP is a pediatrician at Nemours duPont Pediatrics, Villanova, PA.