vitamin K molecules

Variations of the vitamin K molecule.

A small but increasing number of parents are refusing vitamin K injections for their newborns, an intervention recommended since 1961. This is yet another example of the difference between a science-based and philosophy-based approach to medicine. Science has given us the tool of knowledge, and in medicine that knowledge can have very practical applications.

The term “vitamin” was coined in 1912 by the Polish biochemist Kazimierz Funk. A vitamin is an organic nutrient that an organism requires in small amounts but cannot synthesize in adequate amounts and therefore must obtain from the diet. Knowledge of specific vitamins, their food source, and their biochemical activity in the body, has allowed medical scientists to cure many serious nutritional diseases, such as scurvy, rickets, and blindness.

The Vitamin K family are derivatives of 2-methyl-1,4-naphthoquinone, a fat-soluble molecule. It is a cofactor necessary for the formation of factors that function in blood clotting and in bone formation. The primary effect of vitamin K deficiency is therefore bleeding. Infants are at risk for vitamin K deficiency because this molecule does not cross the placenta well. Infants are therefore born relatively deficient in vitamin K. Further, breast milk contains little vitamin K (regardless of the mother’s diet) so infants are at risk for vitamin K deficiency until they start eating solid food at around 6 months (see Clay Jones’ post on the topic here).

The standard of care for many decades has been to give all newborns a vitamin K intramuscular injection. This contains enough of the vitamin to cover them for 6 months until they start getting enough vitamin K in their diet.

Without supplementation, there is an incidence of vitamin K deficiency bleeding (VKDB) in the first week of life of 0.25-1.7%. There is also a late VKDB that is more severe but has a lower incidence of 4.4-7.2 per 100,000 live births. Bleeding most commonly occurs in the brain, and when severe it can be devastating and even fatal.

A single injection of vitamin K at birth significantly reduces the risk of VKDB. In fact, it virtually eliminates the risk. Recent studies looking at infants who have VKDB show that most or all of them did not receive vitamin K prophylaxis. This is a simple, safe, and effective preventive measure, essentially just giving a vitamin to newborns, that prevents a common and potentially devastating outcome. Why would anyone refuse such a clear homerun intervention?

As you might suspect – ideology can trump science and reason. A study published this week in Pediatrics by Sahni et. al. found that 0.3% of those in the study refused neonatal vitamin K. Those who did refuse were 14.6 times more likely to also have refused all recommended vaccines up to age 15 months. They were also 4.9 times more likely to have a planned home birth, and 3.6 times more likely to have delivered at a birth center. A New Zealand survey also published this year found that 100% of medical staff, but only 55% of midwives, agreed that all newborns should receive vitamin K.

One way to interpret this data is that there is a pattern of distrust of the medical establishment or distrust of science in general, and reliance upon so-called “alternative” approaches to birth and childcare. In other words, this is a result of ideology trumping science. As a result, there is an increasing incidence of early and late bleeding in infants.

The numbers of refusals are still low, but are rising fast, clustering in certain centers and hospitals. A recent Tennessee abstract found that in one hospital the refusal rate was as high as 3.7%. They also found that:

Of 102 vitamin K refusers surveyed, 47 (46%) responded; 31/47 (66%) identified bleeding as a risk of refusing prophylaxis. The leading reasons for refusal were desire for a natural birthing process (43%) and believing prophylaxis was unnecessary (43%). Hepatitis B vaccine and erythromycin eye ointment were also refused by 65% of respondents.

In other words, an irrational adherence to the naturalistic fallacy was largely to blame. This was possible combined with misinformation, but I have to wonder if the bleeding risk excuse was simply a post-hoc justification and not the true reason for refusal. Further, we see that those who refuse vitamin K also refuse other recommended interventions, including erythromycin eye ointment used to prevent blindness.


In my opinion, what we are seeing here are the downstream effects of the “alternative medicine” philosophy and world-view. Promoters of CAM often instill a general distrust in science and the institution of medicine. They promote dubious treatments with the notion that “natural” (even though poorly defined) is somehow inherently superior, and therefore interventions that seem technological are to be feared.

They have been unfortunately successful in marketing their philosophy. As a result there are parents who refuse for their newborn children safe and effective interventions supported by solid scientific evidence.


Posted by Steven Novella

Founder and currently Executive Editor of Science-Based Medicine Steven Novella, MD is an academic clinical neurologist at the Yale University School of Medicine. He is also the host and producer of the popular weekly science podcast, The Skeptics’ Guide to the Universe, and the author of the NeuroLogicaBlog, a daily blog that covers news and issues in neuroscience, but also general science, scientific skepticism, philosophy of science, critical thinking, and the intersection of science with the media and society. Dr. Novella also has produced two courses with The Great Courses, and published a book on critical thinking - also called The Skeptics Guide to the Universe.