Neonatal plasma vitamin K1 levels following oral and intramuscular administration of vitamin K1.

Vitamin K1 levels were measured by high performance liquid chromatography in cord blood (n = 33) and at the age of 97-120 h after administration of 2 mg of vitamin K1 orally (n = 88) or 1 mg of vitamin K1 by im injection (n = 88). Vitamin K1 levels were less than 0.05 micrograms/l in cord blood. The mean (range), SEM, mode and median values (micrograms/l) for the infants given oral vitamin K1 were 17.99 (1-56), 1.25, 8 and 15.5 and those for the infants given im vitamin K1 15.83 (2-57), 1.01, 11 and 14, respectively. The t-test showed no significant difference in the mean values (p = 0.09) in the infants given oral or im vitamin K.