Babies are typically born with low levels of vitamin K as it doesn’t cross the placenta during pregnancy. A deficiency of vitamin K can cause bleeding in the stomach and brain of newborns, with complications resulting in life-threatening consequences or the risk of permanent brain damage.
This is called vitamin K deficiency bleeding (VKDB)–previously known as hemorrhagic disease of the newborn (HDN). Even if an infant has other risk factors or diseases, such as hemolytic disease of the fetus and newborn, they are still at risk of VKDB, and treatment will need to be tailored to each patient to avoid further complications. To prevent bleeding and the onset of VKDB, an injection of 0.5 to 1 mg of vitamin K is given to all newborns within six hours of birth as standard procedure.
What is the role of vitamin K and how is it produced in the body?
Vitamin K is fat-soluble, meaning it is stored in fat tissue and liver. It is crucial to bone health, blood clotting and wound healing. If levels of vitamin K are too low, this can lead to uncontrolled bleeding and hemorrhage, and osteoporosis.
It is found in green vegetables, and it is also produced by the bacteria in the intestines. Newborns don’t receive vitamin K during pregnancy and breast milk is low in vitamin K, and they aren’t able to produce enough vitamin K until at least 6 months of age. Vitamin K deficiency is rare in adults as the body only requires small amounts for blood clotting and dietary intake and production in the gut is usually adequate.
Administration of vitamin K by intramuscular injection at birth is the most effective option to increase low levels of vitamin K to prevent the onset of VKDB, which can occur within the first 24 hours or as late as 7 days following delivery. Oral doses of vitamin K have been trialed and found to be less effective as the newborn is not able to properly absorb the vitamin through the stomach and intestines.
What are the benefits of vitamin K in newborns?
In newborns, vitamin K supplementation is essential to clot the blood, to prevent the onset of VKDB and complications that could cause long-term neurological damage or death.
What are the risks or side effects of vitamin K in newborns?
In full term newborns, the reported side effects are limited to pain or swelling around the site of the vitamin K injection. No long-term effects have been recorded.
In preterm newborns, the dose is reduced to 0.3 mg/kg for an infant weighing <1000 mg, as there is a risk of anemia associated with an overdose of vitamin K.
