L Carnitine: Benefits, Side Effects, FAQ, Sources, and Dosage L Carnitine is a vital nutrient that plays a key role in energy production by helping transport fatty acids into the mitochondria, where they are converted into fuel. Maintaining optimal L carnitine L Carnitine plays an important role in the larger metabolism equation: helping your body use fat efficiently as fuel. Learn more about the science on this week's post on The Wellness Edit. Carnitine metabolic disorders and novel clinical approaches: Mechanistic insights from deficiency management to liver and kidney disease treatment ScienceDirect