The Effect of L-carnitine Supplementation on Liver Function, Folate and Vitamin B12 Levels in Patients with Type 2 Diabetes Mellitus: A Randomized, Double-Blind, Clinical Trial

Carnitine is necessary for allowing the long-chain fatty acids to pass the inner mitochondrial membrane to induce β -oxidation. Lack of carnitine and abnormalities of mitochondria play an important role in forming fatty deposition in the liver, and hence, developing steatohepatitis. Carnitine and acylcarnitine identified in human erythrocytes and intra-erythrocyte acetylcarnitine have a significant relationship with the plasma levels. Methods: The present study was conducted to investigate the possible effects of L- carnitine on liver function, folate and vitamin B12 levels in patients with type 2 diabetes mellitus (T2DM). In this study, 70 patients with T2DM were randomly assigned to either a L-carnitine (CG) and a placebo group (PG). For 12 weeks, the first group received 1000 mg/d oral L-carnitine, whereas the second group received 1000 mg/day wheat starch as placebo. The alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), folate, Vitamin B12, complete blood count (CBC) including blood cells and indicators related to anemia were assessed at baseline. Results: 64 patients managed to complete the study (32 in each group). The results indicated that consumption of L- carnitine compared with placebo had no significant effect on liver enzymes, folate, vitamin B12, and CBC with differential. Conclusions:  Daily intake of 1000 mg L-carnitine for 12 weeks had no effect on liver function and anemia indicators including CBC, folate, and vitamins B12.