Does my baby need a vitamin K shot?

For decades, the American Academy of Pediatrics (AAP) has recommended supplementing low levels of vitamin K in newborns with a single shot of vitamin K given at birth. All newborns have low levels of vitamin K, which is an essential substance for blood clotting in our bodies. 

Without enough vitamin K, a newborn may have unexpected bleeding in the immediate postpartum period, or experience vitamin K deficiency bleeding (VKDB). VKDB is a serious and potentially life-threatening cause of bleeding in infants up to 6 months of age. 

Why do newborns have low levels of vitamin K? 

All babies are born with very low levels of vitamin K because it doesn’t cross the placenta well, and the immature liver of a newborn has limited ability to use and store the available vitamin K. As a result, newborns are at greater risk for serious complications should they have any type of bleeding (externally or internally) before their body is able to make its own vitamin K by about 3 months of age. 

How and when is the shot given?

When administered right after birth, vitamin K is given as an intramuscular injection of 0.5 mg to 1 mg. If you are delaying health interventions such as eyedrops, weighing, etc. during the first “golden hour” so that your baby has every opportunity to breastfeed, vitamin K can be administered at the same time as those other interventions, shortly after the first hour. Or, the shot can be given while your baby is skin-to-skin with you, or breastfeeding, which may reduce your baby’s pain.

A single shot of vitamin K is all your baby needs, whether she is breastfed or formula-fed. Parents who choose to forgo the shot and give their baby vitamin K orally need to know that multiple doses are required. Moreover, studies show that oral dosing does not provide the same protection that a single injection provides. 

What are the risks if I refuse a Vitamin K shot for my baby?

Infants who don't receive a vitamin K shot are 81 times more likely to develop late onset (between 2 to 6 months of age) VKDB than infants who do receive it at birth. Since becoming a routine part of newborn care, the administration of vitamin K at birth has been so effective at eliminating VKDB that many pediatricians have never seen a case. Parents who are reluctant to give their baby a vitamin K shot need to know that there is an immediate risk when babies do not receive the shot, and that the risk persists for several months. 

Unlike vaccinations, there is no “delayed schedule” to reduce the risk. A baby who does not receive the vitamin K shot is at risk of serious bleeding until her body produces enough of the vitamin, months after birth. 

While the percentage of infants with vitamin K deficiency is low, the condition can occur without warning in otherwise healthy babies. The results can be devastating with intestinal bleeding, brain bleeding, brain damage, and even death. About half of all babies who develop VKDB have bleeding in their brain. There is ample evidence to show that administration of vitamin K can prevent this life-threatening condition in your baby, and no evidence to show that it poses any health risks.

Last updated June 20, 2021

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