Broad EM, Bolger C & Galloway SD (2006) Dietary carnitine intake and carnitine status in endurance-trained males. Nutrition and Dietetics, 63 (3), pp. 148-154. https://doi.org/10.1111/j.1747-0080.2006.00068.x
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.
urinary carnitine excretion
Nutrition and Dietetics: Volume 63, Issue 3