Prophylaxis of vitamin K deficiency in infancy.

A prospective study was performed in Okazaki, Japan, to attempt to establish a more effective system of prophylaxis for vitamin K deficiency in infancy (VKDI). During the first year, a Normotest (Hepaplastintest) was performed in all infants at one week and at one month of age. Two mg of vitamin K was administered orally to those whose Normotest values were below 40%. i.e., the non-prophylactic administration of vitamin K (NPVK). During the second year of the study, all newborn infants received prophylactic vitamin K (PVK) within 24 hours of birth and at one week of age. The dosage was repeated at one month of age depending on the Normotest value. A total of 7,059 infants, comprising 93.3% of the live births in the city of Okazaki, were enrolled in this study. Data from 5,431 of these infants were used in the analysis of the results. In the NPVK group, 20 of the 2,791 infants had Normotest values below 40% at one month of age while 20 of the 2,640 in the PVK group had low values despite the prophylactic administration of vitamin K. Considering the prevalence of low Normotest values (less than or equal to 40%) at one month of age and the predicted Normotest values, it was concluded that the month of birth (June-September), the age of the mother (21-29 years), the birth order (first-born) and male sex are risk factors for vitamin K deficiency in infancy.