Is l-carnitine supplement beneficial in cases of nash to reduce elevated alt? what is the proper dose for 24 y bmi 19.5 weight of 59 and height 174cm

Yes, 1000 mg 2x/day: L-carnitine is proven to help non-alcoholic steatohepatitis including lowering alt. The research study that showed this used 1000 mg 2x/day which would be a reasonable dose for you. See http://www.Ncbi.Nlm.Nih.Gov/pubmed/20068559 i also advise a low-glycemic diet rich in vegetables & fruits & low in sugars & grains- see http://diet.Lovetoknow.Com/wiki/diet_for_fatty_liver &/or dr. Fuhrman's diet.