Cholecalciferol in Chronic Inflammatory Bowel Diseases

In this research project, the investigators want to find out whether the additional intake of vitamin D further reduces the inflammatory events in the intestines of IBD patients. There are three groups of subjects: the 1st group takes a capsule of 24,000 IU per week, the 2nd group takes 24,000 IU per month, the 3rd group is the control group. The intake extends over 6 months during the autumn and winter period.

Inclusion Criteria:Confirmed IBD diagnosis; Age ≥ 18 yearsExclusion Criteria:Hypercalcaemia defined as serum calcium value >2.70 mmol/l; Hyperparathyreoidism defined as serum iPTH value >65 ng/l; Hypoparathyreoidism defined as serum iPTH value <15 ng/l; Renal insufficiency defined as eGFR < 30 ml/min; Anamnesis of: Propensity to form calcium-containing kidney stones, Impaired renal calcium or phosphate excretion, Sarcoidosis; Pregnancy or lactation; Supplementation of vitamin D >200 IU/d (5μg/d) during study period; Administration of products that have a potential interaction with cholecalciferol, e.g. phenytoin, rifampicin, barbiturates, actinomycin, imidazole-antifungals