Objective: To evaluate the literature describing use of oral vitamin K(1) (phytonadione) to prevent late vitamin K deficiency bleeding (VKDB) in neonates when injectable vitamin K preparations are not available.
Data sources: Articles were retrieved through MEDLINE (1946-February 2012) using the terms vitamin K, vitamin K deficiency bleeding, newborn, neonate, and prophylaxis. Reference citations from publications identified were reviewed.
Study selection and data extraction: All articles published in English on the use of prophylactic oral vitamin K in neonates were evaluated. The largest epidemiologic studies discussing the efficacy of continuous oral vitamin K prophylaxis were reviewed. Individual, smaller clinical trials were not reviewed.
Data synthesis: For prevention of early, classic, and late VKDB, use of intramuscular vitamin K 1 mg is preferred over oral administration because of superior efficacy. Single oral doses protect against early VKDB, but multiple oral doses are needed for late VKDB prophylaxis, especially in exclusively breast-fed neonates. Continuous oral dosing regimens used in the literature vary; European epidemiologic data suggest the lowest rates of late VKDB with oral vitamin K 1 mg at birth followed by 25 μg daily for 13 weeks, or 2 mg at birth followed by 1 mg weekly for 3 months. Limited data describe the use of oral prophylactic vitamin K in high-risk patients (eg, premature neonates, biliary abnormalities).
Conclusions: While there are data supporting effective oral vitamin K dosing regimens for prevention of late VKBD in exclusively breast-fed neonates, lack of an appropriate oral dosage form prevents routine use of this technique in the US. In times of drug shortage, injectable vitamin K preparations should be reserved for use in neonates. If injectable vitamin K is not available, clinicians should choose the most practical method of administering oral vitamin K based on the oral products available.