Carnitine is widespread in two isomeric configurations:
- L-carnitine: metabolically active; it is characterized by a very low toxicity
- D-carnitine: it is considered toxic for humans, as it inhibits the endogenous synthesis of L-carnitine.
L-carnitine is contained in most foods of animal origin. Due to the metabolic role it plays, it is widely used for the formulation of certain slimming food supplements or aimed at improving sports performance. At room temperature and in purity, carnitine appears as a water-soluble white powder.
with a long chain to move from the cytosol into the mitochondria, in the physiological field carnitine is considered an indispensable factor for the beta-oxidation of lipids, especially in muscle cells. For this reason, many believe that by increasing the concentration of carnitine in the diet it is possible to obtain an increase in the actual consumption of fatty acids, which may mean an "acceleration of weight loss or, in endurance sports, also an improvement in performance. In reality this is not the case but, in order to understand the reasons for this conclusion, it is necessary to take a small step backwards, so let's talk about the real effectiveness of carnitine., regarding its metabolic importance, carnitine was baptized vitamin BT.
However, it was soon discovered that, starting from the precursors lysine and methionine, the organism - especially in the liver but also in the kidneys, in conditions of perfect functioning - is able to produce it, fully satisfying its metabolic requirements. Since then, carnitine has not it was more considered a vitamin, but a vitamin-like factor, undoubtedly fundamental but not at all "essential".
