We found a level of 20.8 +/- 3.4 mug/dl of vitamin K1 (VK1) in Intralipid 20% and initiated a study based on the follow-up of children receiving total parenteral nutrition without any other exogenous VK1 intake than from Intralipid 20% (1 g/kg/day). This lipid administration was sufficient to cover the needs during a study period of 4 to 29 weeks.