Dietary carnitine intake and carnitine status in endurance-trained males

Abstract

Background:  Carnitine is an integral component of fatty acid transfer into the mitochondria, and also buffers excess intramitochondrial acyl-CoA. It has previously been suggested that athletes may be at risk of low carnitine status and could therefore benefit from carnitine supplementation. Objective:  To report the habitual dietary carnitine intakes of endurance-trained adult males, and to determine whether they are at risk of carnitine insufficiency by measuring plasma and urinary carnitine concentrations. Methods:  Fourteen non-vegetarian endurance-trained males completed a seven-day weighed food record and exercise logs to determine habitual dietary carnitine intake. Resting venous blood samples and 24-hour urine collections were used to determine plasma carnitine concentration and urinary carnitine excretion. Results:  The mean dietary carnitine intake was 64 (range 21-110) mg/day. Mean±SD resting plasma total carnitine was 44±7µmol/L and acyl:free carnitine ratio was 0.28±0.11, which were within normal ranges. Urinary carnitine excretion was 437±236µmol/day. There was no correlation between dietary carnitine intake or dietary macro- and micronutrients and plasma carnitine or urinary carnitine excretion. Conclusion:  The results of the present study indicate there is no evidence that endurance-trained males consuming a mixed diet are at risk of carnitine insufficiency.