The invention concerns the production of salts or chelates of methyl donors, in particular S-adenosyl-L-methionine or SAMe and betaine or N,N,N-trimethylglycine, with phytic acid or with phosphorylate inositol, possibly partially salified with metal cations, with the formation of stable, totally natural, compounds having a biological activity typical of the starting methyl donors and also combined with, and enhanced by, the biological activity typical of phytic acid or of inositol. The invention also concerns nutraceutical, pharmaceutical, dietary, phytopharmaceutical or veterinary compositions comrising one or more salts or complexes of methyl donors with phytic acid or its derivatives and the method for the synthesis thereof.
