Low vitamin D status may be associated with Crohn's disease. A pilot study was performed in patients with mild-to-moderate Crohn's disease to determine the dose of vitamin D needed to raise serum vitamin D levels above 40 ng/ml.
Patients were evaluated for severity of symptoms using the Crohn's disease activity index (CDAI) and patients with mild-to-moderate (150–400 CDAI scores) Crohn's disease were entered into the study (n=18). Vitamin D3 oral therapy was initiated at 1,000 IU/d and after 2 weeks, the dose was escalated incrementally until patients' serum concentrations reached 40 ng/ml 25(OH)D3 or they were taking 5,000 IU/d. Patients continued on the vitamin D supplements for 24 weeks. CDAI, quality of life measures, bone mineral density, dietary analyses, cytokines, parathyroid hormone, calcium, and several other laboratory measurements were evaluated at baseline and after 24 weeks supplementation.
Fourteen of eighteen patients required the maximal vitamin D supplement of 5,000 IU/d. Vitamin D oral supplementation significantly increased serum 25(OH)D3 levels from 16±10 ng/ml to 45±19 ng/ml (P<0.0001) and reduced the unadjusted mean CDAI scores by 112±81 points from 230±74 to 118±66 (P<0.0001). Quality-of-life scores also improved following vitamin D supplementation (P=0.0004). No significant changes in cytokine or other laboratory measures were observed.
Twenty-four weeks supplementation with up to 5,000 IU/d vitamin D3 effectively raised serum 25(OH)D3 and reduced CDAI scores in a small cohort of Crohn's patients suggesting that restoration of normal vitamin D serum levels may be useful in the management of patients with mild–moderate Crohn's disease.