What is Vitamin K and what does it do in the body?
Vitamin K is a fat-soluble vitamin needed for blood clotting. It is named after the German word for clotting—Koagulation. We cannot make Vitamin K ourselves, and we don’t store it very well in our body. We get Vitamin K1 (also known as phylloquinone) from leafy green vegetables. We can also get Vitamin K2 (menaquinone) from bacteria that live in our intestinal tracts.
Vitamin K1 from plants makes up about 90% of our overall Vitamin K levels, while Vitamin K2 from bacteria makes up only about 10% of our overall Vitamin K intake. (Shearer 2009; Lippi and Franchini 2011; Polin, Fox et al. 2011).
Foods that are rich in Vitamin K1 include:
- Leafy green vegetables, such as spinach, kale, swiss chard, and collards
- Brussels sprouts
- Soybean oil
Vitamin K is necessary for our bodies to activate certain molecules (also known as clotting factors) that help the blood to clot. The blood clotting factors are there in normal numbers at birth, but not activated fully due to low levels of Vitamin K. If we do not have enough Vitamin K, then we cannot activate these molecules. So a Vitamin K deficiency makes our blood less able to clot.
For the most part, our bodies can continue to clot appropriately with low Vitamin K levels. However, as the levels get lower and lower, we can suddenly reach a point where our bodies can no longer clot and we start to bleed spontaneously. The level that you have to get down to for bleeding to start varies from person to person. When the bleeding will occur is completely unpredictable (Shearer 2009). Ref: EvidenceBasedBirth
The bottom line
Giving a breastfed infant a Vitamin K1 shot almost eliminates the chance of life-threatening Vitamin K deficiency bleeding, although no method of giving Vitamin K is 100% effective at preventing late VKDB. The only known adverse effects of the shot are pain, bleeding, and bruising at the site of the injection. Out of many millions of injections, there has only been one report of an allergic reaction in recent history.
The single oral dose and the 3-dose regimen of 1 mg oral Vitamin K1 are less effective than the shot at preventing late VKDB.
Data from some countries suggest the 3-dose regimen of 2 mg oral Vitamin K1 (at birth, 4 to 6 days, 4 to 6 weeks) is also less effective than the shot, although it’s possible that there is not a significant difference between these two options in their ability to prevent late VKDB (Mihatsch et al. 2016). Surveillance data shows that both the shot and the 3-dose regimen of 2 mg get the incidence of late VKDB down to fewer than 1 in 100,000 births. It is important for parents to administer all 3 doses in order for the oral regimen to help lower the risk of late Vitamin K deficiency bleeding.
The Danish regimen of 2 mg oral Vitamin K1 after birth and then 1 mg orally each week for 3 months also gets the incidence of late VKDB down to fewer than 1 in 100,000 births. This oral regimen has been shown to protect infants at higher risk (who have undiagnosed gallbladder disease).
Recently, there have been many myths, misconceptions, and misinformation floating around the internet and social media about Vitamin K. It is important that parents look at the facts so that their consent or refusal is informed. Right now, parents who have been declining Vitamin K may not have all the information, or they may have been given inaccurate information.
Read the full article here: https://evidencebasedbirth.com/evidence-for-the-vitamin-k-shot-in-newborns/