Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis Table 1 from The effects of L carnitine levels on L carnitine levels decrease with age, contributing to aging and a decline in mitochondrial function. The list doesn't stop there. L carnitine supports: Joint health L carnitine has been shown to support joint comfort 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. Lypo Spheric Acetyl L Carnitine Full article: Effects of high dose L carnitine supplementation on diaphragmatic function in patients with respiratory failure: A randomized clinical trial