Administration of Vitamin K to newborns: implications and recommendations.

The review by Drs. Brousson and Klein (see pages 307 to 315 of this issue) identifies controversies surrounding the administration of vitamin K to babies shortly after birth. Controlled studies comparing the effect of oral and intramuscular administration are unlikely to be conducted because of the large number of subjects needed. The evidence presented in the review should dispel concerns that intramuscular administration may be associated with childhood cancer. Oral administration of a single dose of vitamin K soon after is associated with significant biochemical vitamin K deficiency by 1 month of age, but the relation of biochemical abnormality to clinical manifestations of late hemorrhagic disease of the newborn is less clear. Epidemiologic studies indicate a small, but significant, increase in the incidence rate of hemorrhagic disease after oral administration of vitamin K (1.0 to 6.4 incidents per 1000 000 infants), compared with the incidence rate after intramuscular administration (0.25 incidents per 100 000 infants). Although repeated oral doses of vitamin K may be and effective alternative regimen, there is no approved oral vitamin K formulation, there are concerns about patient compliance, and there has been limited investigation of such regimen. Therefore, intramuscular administration of a single dose of 1.0 mg of vitamin K shortly after birth is recommended.