Vitamin K1 diffusion across the placental barrier in the gravid female rat.

The hemorrhagic disease of the newborn can be prevented by administration of vitamin K1. The modes of utilization of the vitamin need to be studied in the mother and child. An experimental pharmacokinetic study was conducted, using the gravid female rat. Results showed rapid intestinal absorption of phylloquinone. The fetus plasma concentration rose from 8.6 micrograms/l at time 0 to 0 to 44.3 micrograms/l at 8 h. Such an increase is an evidence of phylloquinone diffusion across the placenta. The phenomenon requires a high gradient. On the other hand, maximum plasma concentrations are not reached until the 8th hour.