[Study on changes of serum vitamin K1 level and K dependent coagulation factors in patients with coumarin derivatives (warfarin) therapy].

Serum level of vitamin K1 (= phylloquinone, hereinafter K1) and K dependent blood coagulation factors were determined by HPLC in normal subject, liver cirrhosis, hepatocellular carcinoma, acute hepatitis, chronic hepatitis, chronic renal failure with hemodialysis and patients under warfarin therapy. Normal range of serum K1 concentration was decided on 0.20-2.30 (0.87 +/- 0.53, n = 96) ng/ml. Serum K1 level showed no significant differences among normal subject, various diseases and warfarin therapy. Correlation between serum K1 level and F-VII (r = 0.879, p less than 0.001) or protein C activity (r = 0.839, p less than 0.01) was found in patients whose thrombotest was 20% and less. However serum K1 level didn't correlate with any K dependent coagulation factors in patients if thrombotest was over 20%.