There is provided a composition comprising: A) serine, glycine, betaine, N- acetylglycine, N-acetylserine, dimethylglycine, sarcosine and/or phosphoserine B) N-acetyl cysteine, cysteine and/or cystine C) optionally carnitine, deoxycarnitine, gamma-butyrobetaine, 4- trimethylammoniobutanal, 3-hydroxy-N6,N6,N6-trimethyl-L-lysine, N6,N6,N6-trimethyl-L-lysine and/or lysine and D) nicotinamide riboside, quinolinate, deamino-NAD+, nicotinate D-ribonucleotide, nicotinamide D- ribonucleotide, nicotinate D-ribonucleoside,nicotinamide and/or nicotinate, wherein the molar ratio of A) to D) is between 250:1 and 1.5:1 and the molar ratio of A) to B) is between 16:1 and 1:4. The composition may be used in a method of treatment of a medical condition selected from the group consisting of non-alcoholic fatty liver disease (NAFLD), alcoholic fatty liver disease (AFLD), type 2 diabetes, obesity, insulin resistance and dyslipidemia.
