What is Vitamin K?

by Anna Riley, Midwifery Student, Laurentian University

Vitamin K is a fat-soluble vitamin that is necessary for blood to clot effectively. It is routinely given in North America as an intra-muscular injection to newborn babies shortly after birth, although this is an elective procedure that parents may opt out of if they choose to do so. The reason that it is given to babies is as follows. Babies are born with very little vitamin K in their bodies, in comparison to adults. It is produced subsequently in their intestines by "good" bacteria that colonize the gut after birth. A small number of babies (approximately 1 in 10,000) will develop a disease called Vitamin K Deficiency Bleeding (VKDB) shortly after birth. VKDB is unexpected bleeding that can potentially cause permanent disability, or death. There are three types of VKDB.

Early onset VKDB – occurring within the first 24 hours, this is primarily associated with the use of anti-seizure medication, warfarin and anti-tuberculosis drugs by the mother during pregnancy. It is very rare even in high-risk pregnancies.

Classic VKDB – occurs between days 1 to 7. Approximately 2.2 per 100,000 babies are severely affected. In particular, premature babies who have feeding or absorption problems. It is less frequent in term babies, but can be associated with birth trauma such as bruising from a caesarean birth, forceps or shoulder dystocia. It can also occur in boys who are circumcised less than 8 days after birth.

Late onset VKDB - occurs between 2 to 12 weeks after birth. It affects 4.4 –10.5 per 100,000 babies and is most often associated with underlying problems such as liver disease and cystic fibrosis.

In the absence of any other factors, exclusive breastfeeding is considered a risk factor for classic and late-onset VKDB. Administration of Vitamin K by injection virtually, but not entirely, eliminates the risk of VKDB.

Some things to consider regarding vitamin K:

• All babies have low levels of vitamin K compared to adults. Gradually the level of vitamin K rises through intake of breastmilk and then production in the baby's intestines.
• The amount of vitamin K administered was originally decided by what manufacturers produced, not by research. It is 20,000 times higher than the vitamin K the baby is born with.
• If antibiotics have been administered during labour, or to the newborn, bacterial colonization and therefore vitamin K manufacture in the intestines will be delayed.
• -Immediate cord clamping deprives the baby of 25-40% of their blood volume, and therefore 25-40% of their blood clotting factors.
• VKDB is associated with breastfeeding because formula is high in vitamin K.
• Vitamin K is found both in colostrum and mature milk. Mothers who eat a diet rich in vitamin K pass more to their babies. Eat foods such as cauliflower, broccoli, spinach, kale, cabbage and alfalfa.

The shot hurts and many babies experience swelling and redness at the injection site. Most will cry. This can be upsetting for both the baby and the parents. However, breast milk is known to reduce pain. Ask your care provider to wait until the baby has started to successfully breastfeed before giving the injection whilst the baby is at the breast.

Whatever you decide is best for your baby make sure that your care provider knows your preference. Unless otherwise stated, the vitamin K shot is usually given routinely when your baby is assessed and weighed immediately after the birth.