Why does my baby need a vitamin k injection?

What is Vitamin K?

Vitamin K is a really important vitamin which is found in many foods, and is also made in our intestines by gut bacteria. Our body needs it to make the proteins that allow blood to clot.

Why is Vitamin K important for my baby?

We know that newborn babies may not have enough vitamin K. This is because not much passes from the mum to the baby across the placenta and the newborn baby cannot make vitamin K in the gut as well as they can as they get older.

Being short of vitamin K means that a small number of babies experience bleeding unless they get some extra vitamin K.

Whilst this is mostly not dangerous, in the worst case scenario, this can be serious and happen inside the brain, causing a sort of stroke. This can obviously be catastrophic in a very small number of babies.

This disorder is something called vitamin K deficient bleeding, and it used to be called haemorrhagic disease of the newborn.

How can I avoid this bleeding?

In the UK, the NHS has been offering vitamin K supplements to newborn babies for many years  (since the 1950s) because this prevents this problem entirely. Your midwife should discuss this with you during the pregnancy, and again when you come into hospital to have your baby.

How can I give my baby Vitamin K?

There are two ways this can be given, either by mouth or as an injection into a muscle. The quickest and easiest way is the injection and this is the most effective (CDC), as it only needs to be given once. The baby is given an injection immediately after birth into a leg muscle. This is only needed as one dose and does not need to be repeated and provides all the protection the baby needs.

The second way is by some mouth drops, but these usually need to be given 3 times (usually at birth, at 1 week and again at 1 month of age)  and may be slightly less effective as the amount of absorption is unpredictable. This is a bit more cumbersome as you need to give the doses yourself and giving babies any medicine can be a challenge! (some gets spat out and not swallowed inevitably). Some hospitals have different approaches for babies who are bottle fed and breast fed. This is because breast milk does not contain much vitamin K but formula feed is usually supplemented with vitamin K.

Overall, premature babies and small babies, and those who are exclusively breast fed experience the most benefit from vitamin K. The injection is the version recommended by the NHS and the CDC as the most reliable and effective options (CDC, ).

Is Vitamin K Safe?

The medical literature shows that both options are safe and the benefits of your baby receiving vitamin K far outweigh any possible risks. There are very few risks or downsides and they are very minor. If you choose the injection it obviously causes the baby a small amount of discomfort at the time that the injection is given. It is possible that the baby may get some temporary redness at the injection site. There are very few downsides to the oral supplement, other than inconvenience, babies not liking the taste. 

There were concerns in the early 1990s about there being an association between vitamin K injections and childhood leukaemia (blood cancer), mainly with the injected form. However, the best study to date, published in 2003, which was the UK childhood cancer study looked at over 2000 children who had been diagnosed with cancer and found no association. This is very reassuring, as it confirmed that vitamin K is a safe medication and does not increase the risk of other disorders, including cancer and leukaemia. 

References

• https://www.cdc.gov/breastfeeding/breastfeeding-special-circumstances/diet-and-micronutrients/vitamin-k.html
• https://www.medicinesforchildren.org.uk/medicines/vitamin-k-for-vitamin-k-deficiency-bleeding/
• https://www.nhs.uk/pregnancy/labour-and-birth/after-the-birth/what-happens-straight-after/
• Vitamin K and Childhood Cancer: a report from the United Kingdom Childhood Cancer Study. Br J Cancer 2003 Oct 6;89(7):1228-31. doi: 10.1038/sj.bjc.6601278.