Safety and efficacy of L carnitine supplementation in improving cardiac function of hemodialysis patients: a systematic review and meta analysis International Urology and Nephrology Springer Nature Link Essential L Carnitine Optimal Health Systems Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis Comprehensive review of the expanding roles of the carnitine pool in metabolic physiology: beyond fatty acid oxidation Journal of Translational Medicine Springer Nature Link L Carnitine & Arterial Plaque L Carnitine Premature Mortality Life Extension