Digital Public Defence: Svein Oskar Frigstad Svein Oskar Frigstad at Institute of Clinical Medicine will be defending the thesis “Vitamin D deficiency in Inflammatory Bowel Disease – prevalence, predictors and associations with fatigue and pain (The Vitality Study)” for the degree of PhD (Philosophiae Doctor).

Photo: Private.

The public defence will be held as a video conference over Zoom.

The defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.

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Due to copyright reasons, an electronic copy of the thesis must be ordered from the faculty. In order for the faculty to have time to process the order, it must be received by the faculty no later than 2 days prior to the public defence. Orders received later than 2 days before the defence will not be processed. Inquiries regarding the thesis after the public defence must be addressed to the candidate.

Digital Trial Lecture – time and place

See Digital Trial Lecture.

Adjudication committee

  • First opponent: MD Mia Bendix Rasch, Aarhus University Hospital
  • Second opponent: Associate Professor Eivind Ness-Jensen, NTNU
  • Third member and chair of the evaluation committee: Professor Lars Aabakken, University of Oslo

Chair of the Defence

Professor Ketil Størdal, Faculty of Medicine, University of Oslo

Principal Supervisor

Professor Lars-Petter Jelsness-Jørgensen, Faculty of Medicine, University of Oslo



Vitamin D deficiency in inflammatory Bowel Disease

Inflammatory bowel disease (IBD) consists mainly of Crohn’s disease and ulcerative colitis, which are chronic inflammatory disorders of the gastrointestinal tract. Patients report a variety of symptoms such as diarrhea with or without blood, abdominal pain, weight loss and fatigue.

Numerous reports on the immunomodulating effects of vitamin D have been published, and research does increasingly support the concept that vitamin D may play a role in the clinical course of IBD. Furthermore, several studies have shown that vitamin D deficiency is common in patients with IBD. Prior to the Vitality study, the knowledge of vitamin D status in patients with IBD in Norway was limited.

The goal of this thesis was to investigate the prevalence and possible clinical predictors of Vitamin D deficiency in IBD, and whether a deficiency might be associated with patient reported outcomes such as increased fatigue and pain severity.

We found that vitamin D deficiency was common in a Norwegian outpatient population with IBD, especially in Crohn’s disease, and more prevalent than in the general population. Around half of the patients had vitamin D deficiency. Vitamin D deficiency was associated with increased patient-reported disease activity, a relapsing disease course and higher inflammatory activity. No significant associations between vitamin D deficiency and fatigue, nor between vitamin D deficiency and pain severity were revealed.

Fatigue was associated with burden of symptoms, depressive symptoms and sleep disturbance. Pain severity was associated with clinical disease activity and the female gender.

The role of vitamin D in IBD remains controversial, but our study supports the importance of ensuring at least adequate vitamin D levels in patients with IBD. An unmet need remains, in establishing whether the potential anti-inflammatory effects of vitamin D translates into clinical benefits for patients.

Additional information

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Published Feb. 18, 2022 10:53 AM - Last modified Mar. 4, 2022 10:56 AM