Study	Reason for exclusion
Arteaga‐Vizcaino 95	The groups in this study were either breast fed or formula fed. These groups were then each divided into 2 subgroups which received either oral or no vitamin K. The authors of the study are being contacted to clarify the method of allocation, both to feeding group and to vitamin K.
Felbo 1965	This trial allocated infants to vitamin K or nothing on an alternating month schedule. The outcome was clinical bleeding, but the individual reporting the bleeding was aware of whether the infant had received vitamin K or not. This trial was judged to be very prone to bias and was excluded for this reason.