[Effects of the administration of vitamin K on the activity of Factor II, VII and X in healthy newborns].

The study was designed to know the effect of oral vitamin K (VK) treatment, on clotting factors II-VII-IX-X and the protein induced by VK absence from factor II (PIVCA II) on full term infants. Seventy healthy newborns were studied and each was randomly placed in one of two groups: Group A, newborns that received human milk and milk formula (mixed feeding)and group B, newborns that were exclusively breast fed. These groups were also divided in two subgroups: I received 2mg of VK1 orally and II (control) did not receive VK. Clotting activity of the coagulation factors and PIVCA II was determined from blood plasma obtained immediately after birth and 48 hours after VK administration. Basal activity of the factors analyzed was similar in all groups with values ranging from 25% to 40%. After 48 hours a significant increase in all factors studied and a decrease of PIVKA II was observed in those children who received oral VK. The results suggest that oral VK effectively increases VK dependent factors and prevents the risk of hemorrhagic disease in the newborn, with the advantage of being less traumatic and less risky to the infant than intramuscular VK.