Vitamin K helps blood to clot. Babies are born with very little vitamin K, because it doesn’t cross the placenta well and their gut bacteria (which make vitamin K in adults) has not yet developed. That puts them at risk for vitamin K deficiency bleeding (VKDB) — a rare but potentially devastating condition that usually involves bleeding in the brain (a stroke) or bleeding in the gut.
Here’s a look at why the vitamin K shot is strongly recommended for babies instead of consuming vitamin K by mouth (oral or PO are other terms for this), based on the scientific evidence we know from using both methods of giving vitamin K to babies.
Why is the vitamin K shot recommended for newborns?
Newborns do not have good stores of vitamin K at birth, which means their blood can’t clot well without vitamin K supplementation. Vitamin K deficiency bleeding (VKDB) can occur in the first days to weeks of life; and there’s still a risk of late bleeding for up to 6 months after a baby is born. This late bleeding is the most dangerous, because it can cause things like strokes.
Research over decades shows that a single intramuscular (IM) shot of vitamin K given shortly after birth effectively prevents almost all cases of VKDB. Because of this strong protective effect, pediatric healthcare professionals have recommended the shot for all newborns since 1961. It has virtually eliminated VKDB in places where it is widely used.
How does the shot compare with oral vitamin K?
Some parents wonder whether oral vitamin K could be used instead of the shot. While oral vitamin K can raise vitamin K levels and reduce the risk of early VKDB, there are important differences in how well the two methods work:
- Intramuscular vitamin K protect much better against late VKDB. A single oral dose is still associated with a higher risk of VKDB, and even repeated oral doses do not match the injection’s effectiveness. Oral regimens also require strict adherence to multiple doses over weeks, which can be difficult to maintain especially in the United States, where healthcare systems are more fragmented than in other places like Europe.
- There is no FDA-approved oral vitamin K formulation for newborns in the United States. Also, absorption from the gut may be unpredictable in very young infants whose digestive systems are still developing.
The shot, on the other hand, delivers vitamin K directly into muscle. It bypasses the gut and provides steady stores of the vitamin over months – precisely when a baby needs it most.
What are the concerns or risks?
The vitamin K shot is very safe. There is no credible evidence that links the injection to childhood cancers or other serious long-term problems, despite small older studies that raised concerns decades ago. Most babies tolerate the shot well, and serious side effects, including allergic reactions, are extraordinarily rare.
Choosing not to give the shot, or relying on oral vitamin K, leaves newborns at risk for VKDB, which can result in irreversible brain injury or death.
What are we still learning?
Recent research shows an increase in the number of parents choosing not to give their newborns the vitamin K shot, because of misconceptions about how safe it is and if it is needed for babies (it is). This trend has raised public health concerns because it may lead to more cases of VKDB in infants.
Studies are ongoing regarding the optimal dosing and potential roles of oral vitamin K. However, the current evidence today strongly supports giving newborns the intramuscular shot as the safest and most effective way to prevent vitamin K deficiency bleeding
References
- https://pubmed.ncbi.nlm.nih.gov/27109090/
- https://publications.aap.org/pediatrics/article/149/3/e2021056036/184866/Vitamin-K-and-the-Newborn-Infant
- https://jamanetwork.com/journals/jama/article-abstract/2842444
- https://www.healthychildren.org/English/ages-stages/prenatal/delivery-beyond/Pages/Where-We-Stand-Administration-of-Vitamin-K.aspx
Vitamin K helps blood to clot. Babies are born with very little vitamin K, because it doesn’t cross the placenta well and their gut bacteria (which make vitamin K in adults) has not yet developed. That puts them at risk for vitamin K deficiency bleeding (VKDB) — a rare but potentially devastating condition that usually involves bleeding in the brain (a stroke) or bleeding in the gut.
Here’s a look at why the vitamin K shot is strongly recommended for babies instead of consuming vitamin K by mouth (oral or PO are other terms for this), based on the scientific evidence we know from using both methods of giving vitamin K to babies.
Why is the vitamin K shot recommended for newborns?
Newborns do not have good stores of vitamin K at birth, which means their blood can’t clot well without vitamin K supplementation. Vitamin K deficiency bleeding (VKDB) can occur in the first days to weeks of life; and there’s still a risk of late bleeding for up to 6 months after a baby is born. This late bleeding is the most dangerous, because it can cause things like strokes.
Research over decades shows that a single intramuscular (IM) shot of vitamin K given shortly after birth effectively prevents almost all cases of VKDB. Because of this strong protective effect, pediatric healthcare professionals have recommended the shot for all newborns since 1961. It has virtually eliminated VKDB in places where it is widely used.
How does the shot compare with oral vitamin K?
Some parents wonder whether oral vitamin K could be used instead of the shot. While oral vitamin K can raise vitamin K levels and reduce the risk of early VKDB, there are important differences in how well the two methods work:
- Intramuscular vitamin K protect much better against late VKDB. A single oral dose is still associated with a higher risk of VKDB, and even repeated oral doses do not match the injection’s effectiveness. Oral regimens also require strict adherence to multiple doses over weeks, which can be difficult to maintain especially in the United States, where healthcare systems are more fragmented than in other places like Europe.
- There is no FDA-approved oral vitamin K formulation for newborns in the United States. Also, absorption from the gut may be unpredictable in very young infants whose digestive systems are still developing.
The shot, on the other hand, delivers vitamin K directly into muscle. It bypasses the gut and provides steady stores of the vitamin over months – precisely when a baby needs it most.
What are the concerns or risks?
The vitamin K shot is very safe. There is no credible evidence that links the injection to childhood cancers or other serious long-term problems, despite small older studies that raised concerns decades ago. Most babies tolerate the shot well, and serious side effects, including allergic reactions, are extraordinarily rare.
Choosing not to give the shot, or relying on oral vitamin K, leaves newborns at risk for VKDB, which can result in irreversible brain injury or death.
What are we still learning?
Recent research shows an increase in the number of parents choosing not to give their newborns the vitamin K shot, because of misconceptions about how safe it is and if it is needed for babies (it is). This trend has raised public health concerns because it may lead to more cases of VKDB in infants.
Studies are ongoing regarding the optimal dosing and potential roles of oral vitamin K. However, the current evidence today strongly supports giving newborns the intramuscular shot as the safest and most effective way to prevent vitamin K deficiency bleeding
References
- https://pubmed.ncbi.nlm.nih.gov/27109090/
- https://publications.aap.org/pediatrics/article/149/3/e2021056036/184866/Vitamin-K-and-the-Newborn-Infant
- https://jamanetwork.com/journals/jama/article-abstract/2842444
- https://www.healthychildren.org/English/ages-stages/prenatal/delivery-beyond/Pages/Where-We-Stand-Administration-of-Vitamin-K.aspx
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