Among the possible causes of porphyric crises decrease of caloric intake has been described.
Daniela von Ah Lopes, Marcelo Araújo do Valle, Jéfferson Taguti, Regina Celli ThoméCastro Taguti, Gustavo Navarro Betônico, Fabiana Clemente Medeiros 2008, 'Porfiria aguda intermitente: relato de caso e revisão da literatura Acute intermittentporphyria: case report and review of the literature', Revista Brasileira de Terapia Intensivahttp://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-507X2008000400017. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Moreover, some patients have received treatments that precipitate acute porphyric attacks, such as antibiotics or antiepileptics, causing worsening of symptoms.
Doungporn Ruthirago, Parunyou Julayanont, Supannee Rassameehiran 2016, 'Presentations associated with porphyrias in intensive care units', Southwest Respiratory and Critical Care Chronicleshttp://pulmonarychronicles.com/index.php/pulmonarychronicles/article/view/314. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)