L-ornithine must be supplemented. Fatigue results if L-ornithine is not supplemented. DMT1 which transports iron also transports manganese. With DMT1 dysregulated manganese transport will be dysregulated. Arginase is a manganese containing enzyme that synthesizes L-ornithine. With arginase dysregulated there will be low levels of L-ornithine so L-ornithine must be supplemented. As L-arginine, L-lysine and L-ornithine are all transported by the same transporter, CAT1, L-arginine and L-lysine are not supplemented as L-arginine and L-lysine could block transport of l-ornithine. . Creatine should be supplemented if L-ornithine is supplemented. L-ornithine is an end product inhibitor of the first enzyme in the synthesis of creatine. Manganese levels should be tested for.