The effect of l carnitine supplementation on mortality and clinical outcomes in ventilator dependent critically ill patients with obesity and COVID 19: Protocol for a randomized double blind placebo controlled trial ScienceDirect What's L Carnitine and how Does it Benefit your Overall Health? L Carnitine: The Energy Booster Your Body Loves Turn fat into fuel and power up your recovery with one of our favorite performance vitamins. Boosts metabolism & fat burning If you are like a lot of people, you may have never heard of carnitine but this important nutrient is critical for our body's ability to optimally burn fat required for energy.