However , carnitine supplementation at dosages of ≤ 1000 mg/day ( p = 0.035 ) or equal to 2000 mg/day ( p = 0.013 ) result ed in significant reduction in ALT level , while doses more than 2000 mg/day did not change ALT  significantly .
Carnitine exerts its reducing effect on serum ALT and AST levels only when these aminotransferases are raised or when the duration of supplementation lasts at least 3 months .
Results of the current meta- analysis showed that carnitine supplementation can decrease serum AST and ALT levels significantly , especially when supplementation lasts 3 months or more in patients with elevated serum aminotransferase levels
Potential inhibitory effects of L-carnitine supplementation on tissue advanced glycation end products in patients with hemodialysis.
BACKGROUND AND AIMS Advanced glycation end products ( AGEs ) contribute to cardiovascular disease in patients with hemodialysis ( HD ) . We have recently found that carnitine levels are inversely associated with skin AGE levels in HD patients . We examined whether L-carnitine supplementation reduced skin AGE levels in HD patients with carnitine deficiency . METHODS This was a single-center study . One hundred and two HD patients ( total carnitine levels < 50 μmol/L ) were enrolled and r and omized to either oral administration of L-carnitine ( 900 mg/day ) ( n=51 ) or control ( n=51 ) . After 6 months , metabolic and inflammatory variables , including serum levels of carnitine , were measured . Skin AGE levels were determined by evaluating skin auto-fluorescence with an AGE-reader . RESULTS There were no significant differences of clinical variables at baseline between the  control and L-carnitine therapy group . Thirty-two patients did not complete the assessment or treatment of the study .  Oral L-carnitine supplementation for 6 months significantly increased low-density lipoprotein cholesterol ( LDL-C ) , triglycerides , total , free , and acyl carnitine levels , while it decreased alanine transaminase , acyl/free carnitine ratio , β₂-microglobulin , and skin AGE values . Change in total carnitine values from baseline ( Δtotal carnitine ) and Δfree carnitine were inversely associated with Δskin AGE levels  in L-carnitine-treated patients ( p=0.036 and p=0.016 , respectively ) . In multiple regression analysis , Δfree carnitine was a sole independent determinant of Δskin AGEs ( R²=0.178 ) . CONCLUSIONS The present study demonstrated that oral L-carnitine supplementation significantly decreased skin AGE levels in HD patients with carnitine deficiency . These observations suggest that supplementation of L-carnitine might be a novel therapeutic strategy for preventing the accumulation of tissue AGEs in carnitine-deficient patients with HD
However , carnitine supplementation at dosages of ≤ 1000 mg/day ( p = 0.035 ) or equal to 2000 mg/day ( p = 0.013 ) result ed in significant reduction in ALT level , while doses more than 2000 mg/day did not change ALT  significantly .
Carnitine exerts its reducing effect on serum ALT and AST levels only when these aminotransferases are raised or when the duration of supplementation lasts at least 3 months .
Results of the current meta- analysis showed that carnitine supplementation can decrease serum AST and ALT levels significantly , especially when supplementation lasts 3 months or more in patients with elevated serum aminotransferase levels