If you are lacking in any of the elements necessary for the production of l-carnitine, such as niacin, vitamin B1, B6, C, methionine, lysine, or iron, you might benefit from taking l-carnitine supplements
Senescent erythrocytes are characterized by loss of surface area and volume [66], increased cell density [67], reduced deformability [68], cation loss [69], membrane desialylation [70], enzymatic dysregulation [69], oxidative stress [71], hemichrome abundance [69], elevated levels of glycated hemoglobin [72], reduced expression of phagocytosis-inhibiting CD47 [73], altered protein 4.1a/protein 4.1b ratio [74], etc
32 Nucleophilic Substitution Reaction of the Hydroxyl Group on L-Carnitine with Propionyl Chloride The hydroxyl group on L-carnitine can also react with nitric acid to form organic nitrate salts
(PubMed) Piscitelli SC, Burstein AH, Welden N, Gallicano KD, Falloon J