In most hospital deliveries, vitamin K is administered via injection shortly after birth as part of the standard regimen of newborn care. Some parents choose to opt out of this particular intervention for fear that the shot may do harm or because they see it as unnecessary. Understanding both sides of the issue can help parents-to-be decide whether or not their baby needs vitamin K supplementation.
The purpose of a vitamin K shot for a newborn is to prevent early vitamin K deficiency bleeding, or VKDB. This disorder, formerly known as classic hemorrhagic disease of the newborn, occurs when a baby is born deficient in vitamin K. This deficiency can cause brain bleeding to develop within the first few weeks of life. Vitamin K supplementation immediately after birth is the only known method to prevent potentially fatal hemorrhaging in vulnerable babies. Bleeding that begins after the third week is called late VKDB and can be prevented with oral vitamin K supplementation over the first two to three months of life. Infant formula contains high levels of vitamin K, but breastfed babies who did not get the post-birth vitamin K shot may need oral supplements through the 12th week of life.
Both early and late VKDB are extremely rare. Without any form of vitamin K supplementation, early VKDB occurs in only 1.8 babies per 100,000 and late VKBD occurs in 5 out of every 100,000. In the past, small studies have indicated a possible link between vitamin K supplementation and the incidence of childhood leukemia, but this link was limited to oral supplementation, not the shot. However, a large 2003 study published in the "British Journal of Cancer" found no link whatsoever between childhood leukemia and vitamin K supplementation.
Pregnant women who are on anti-epileptic medication have babies at high risk for VKDB, so the administration of the vitamin K shot at birth is especially important for these infants. Babies who were exposed to alcohol or drugs while in the womb are also at higher risk of bleeding complications after birth. Other risk factors that may increase a baby's need for vitamin K include any trauma during birth, such as forceps or vacuum extraction delivery, or shortly after birth, such as circumcision or other surgical procedures.
Before opting out of the vitamin K shot for your baby, talk with a doctor about any concerns you might have and consider whether your child will be at risk for any complications that might necessitate supplementation. One alternative for breastfeeding mothers who forego the shot for their baby is for the mother to take 1 mg of vitamin K daily for up to 12 weeks in order to raise vitamin K levels in her breast milk.