Vitamin K regimens and incidence of childhood cancer in Denmark

Abstract
A national cancer registration system has been operating in Denmark since 1942.5 Regimens for administration of vitamin K to neonates have varied greatly over the 50 years of notification. No vitamin K was given to either newborns or mothers before 1955, we could define a non- exposed cohort as all children born in Denmark during 1945-54 (n=835 430).