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.