Background: IV lipid emulsions contain vitamin K in substantial quantities and in 1989, we therefore stopped supplying vitamin K1 to patients receiving home parenteral nutrition (HPN). Methods: Nine patients (group I) receiving HPN before 1989 (10 mg IV vitamin K-1 supplementation weekly until 1989, which was discontinued thereafter) and six patients with an initial low plasma vitamin K-1 concentration (related to their malabsorption) (group II) receiving HPN after 1989 were studied. Prothrombin time (PT), plasma vitamin K-1 concentration, and vitamin K-1 content in lipid emulsions were measured throughout the period of HPN. Results: All lipid emulsions, except for Eurolip 20% and Clinoleic 20% (Baxter SA, Maurepas, France) contained vitamin K-1, with concentration ranges from 179 +/- 39 to 353 +/- 78 ng/L. Group I patients had an initial high plasma vitamin K-1 concentration due to the vitamin K-1 supplementation. After this supplementation was discontinued, plasma vitamin K-1 decreased and remained in normal ranges with a normal PT. Throughout the HPN period after 1989, patients received 255 +/- 104 mu g of vitamin K-1 weekly through lipid emulsions. The PT and plasma vitamin K-1 concentrations in group II patients were restored by lipid emulsions, which contained 418 +/- 143 mu g/wk of vitamin K-1. Conclusions: In patients receiving TV lipids (except for Eurolip and Clinoleic), a normal vitamin K-1 status can be maintained during long-term HPN without vitamin K-1 supplementation. However, vitamin K supplementation cannot be abandoned until the vitamin K content of emulsions is standardized by manufacturers. A weekly supply of 260 to 400 mu g of vitamin K-1 is enough to maintain and even restore a normal vitamin K-1 status in HPN.