According to IKDSG guidelines, KD use is strictly contraindicated in patients with a deficiency of carnitine (primary), carnitine palmitoyltransferase (CPT) 1 or 2, carnitine translocase, pyruvate carboxylase, medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD), long-chain acyl-CoA dehydrogenase (LCAD), short-chain acyl-CoA dehydrogenase (SCAD), and disorders of fatty acid β-oxidation and porphyria. Here, ACADS is linked to porphyria.