An evaluation of serum free carnitine level in CAPD patients in relation to dietary intake, nutritional status and CAPD adequacy and duration.Food diaries, nutritional (total body mass, lean body mass, serum level of proteins, carnitine, cholesterol) and adequacy (Kt/V, PCR, tCcr, EN) parameters were obtained in 23 CAPD patients.Normal carnitine level (41.8+/-6.7 micromol/l) was found in 17 patients being on CAPD through 11.1+/-9.6 months, whereas in 6 persons treated with CAPD through 9.7+/-4.1 months carnitine level was 25.4+/-5.7 micromol/l. Significant differences between low and normal carnitine groups were in tCcr (82.7+/-16.7 v. 65.9+/-13.2 l/wk/1.73 m2 BSA), effluent volume (10.9+/-0.8 v. 9.9+/-1.5 l/day), effluent glucose concentration (729+/-167 v. 530+/-220 mg/dl) and serum globulin level (22.6+/-6.4 v. 29.3+/-4.4 g/l). Significant correlation coefficients (for n = 23) were found between serum carnitine level and effluent volume (r=-0.509) or plasma globulin level (r=+0.522).Patients with higher CAPD adequacy show lower serum free carnitine levels and this is related to higher effluent volumes.