Should we be concerned about low Vitamin K in newborns?

Might there be a good reason why babies are born with low Vitamin K? If so, are we right to override this?  

One of Informing Consent’s medical advisers, a retired paediatrician, says:  

‘Haemorrhagic disease of the newborn is a real thing and Vitamin K at birth has been in place for decades.  

However, at a biological level, I always worry about something needed by an entire population, because nature has a habit of getting things right!  

Vitamin K levels in cord blood are significantly lower than in maternal blood, but no-one has worked out the biological advantage. 

Newborns’ low Vitamin K levels may allow stem cells in cord blood to better reach areas needing repair after birth, and this benefit may be enhanced by delayed cord clamping.’ 

In the study, ‘Childhood cancer, intramuscular Vitamin K, and pethidine given during labour’, the authors write in their conclusion: 

‘It has always seemed physiologically perverse that evolution should have permitted the development of what is termed Vitamin K deficiency in normal term infants who are breast fed, resulting in a small but definable risk of haemorrhagic disease of the newborn.  

The most likely explanation for this situation is that there is some evolutionary advantage that outweighs this risk.  

The finding of an increased incidence of childhood cancer in children given intramuscular Vitamin K in the neonatal period suggests that a relative deficiency in Vitamin K during this critical phase of rapid growth and development may protect vulnerable tissues from mutagenesis.  

The protection afforded by oral Vitamin K against haemorrhagic disease does not appear to carry the same risk of inducing malignancy, so it may be prudent to use oral rather than intramuscular Vitamin K.’ 

One of Informing Consent’s pharmacological advisers notes: 

‘Newborns universally exhibit low Vitamin K levels due to limited placental transfer, absence of gut microbiota, and low breast milk concentrations.   

This state may reflect an aspect of developmental haemostasis, in which reduced clotting capacity balances thrombotic risk during a critical transition period. Routine IM [intra-muscular] dosing produces a rapid and supraphysiological increase in Vitamin K levels, effectively overriding this state. 

While no strong evidence demonstrates long-term harm from this intervention, it is equally true that evidence disproving subtle or delayed effects is limited, particularly given the difficulty of detecting small shifts in thrombotic or immunological outcomes over time.’