Comparison of the effects of 1,25 dihydroxyvitamin D and 25 hydroxyvitamin D on bone pathology and disease activity in Crohn's disease patients

Background: Vitamin D is essential for osteopenia therapy in Crohn's disease (CD). The active form of vitamin‐D (aVD) is the 1,25(OH)2D. There are no data available whether aVD or plain vitamin‐D (pVD) has any advantage in managing osteoporosis in CD or has any effect on the activity of the disease itself. Our work is a prospective study to compare the effects of aVD and pVD on bone metabolism and the clinical course of CD. Methods: In all, 37 inactive CD patients were involved in the study and divided into 2 age‐, gender‐, and t‐score‐matched groups. Group A was treated with aVD while group B received pVD. Osteocalcin, beta‐CrossLaps, osteoprotegerin, and receptor activator nuclear factor kappa‐B ligand concentrations were estimated at the start of the study and at 6 weeks and 3 and 12 months. The activity of CD was also measured clinically and by laboratory parameters. Results: At week 6 the Crohn's Disease Activity Index (CDAI) scores and concentration of C‐reactive protein decreased (69.44 ± 58.6 versus 57.0 ± 54.89 and 15.8 ± 23.57 mmol/L versus 7.81 ± 3.91 mmol/L, respectively, P < 0.05) parallel with markers of bone turnover (beta‐CrossLaps: 0.46 ± 0.21 ng/mL versus 0.40 ± 0.25 ng/mL, and osteocalcin: 32.29 ± 15.3 ng/mL versus 29.98 ± 14.14 ng/mL, P < 0.05); however, osteoprotegerin concentration (marker of osteoblast activity) increased (3.96 ± 2.1 pg/mL versus 4.58 ± 2.19 pg/mL) in group A, but did not change in group B. Osteocalcin and beta‐CrossLaps concentrations changed more significantly by the 3rd month; however, these changes disappeared by the 12th month. Conclusions: According to our study, aVD has a more prominent short‐term beneficial effect on bone metabolism and disease activity in CD compared with pVD. (Inflamm Bowel Dis 2009)