The role of vitamin D in treated and refractory ulcerative colitis patients: a case-control study

Ulcerative colitis is a form of chronic inflammatory bowel disease (IBD) marked by ongoing inflammation of the mucosal lining that extends from the rectum to the upper part of the colon. Vitamin D regulates immune responses in several autoimmune and inflammatory diseases, including ulcerative colitis. Therefore, the study aims to investigate the role of vitamin D in the pathogenesis and treatment of ulcerative colitis.

This case-control study included 94 participants who were divided into four groups. Group 1: people with ulcerative colitis who responded to treatment (n = 24). Group 2: family members of patients who responded to treatment and did not have the disease (n = 24). Group 3: People with ulcerative colitis who are resistant to treatment (n = 23). Group 4: family members of treatment-resistant patients who does not have the disease (n = 23). Groups 1 and 3 were considered as patient groups (n = 47) and groups 2 and 4 as control groups (n = 47). Blood samples were taken and analyzed for complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum vitamin D levels.

The mean age of treatment-responsive patients (group 1) was 45.88 ± 18.51 years, while treatment-resistant patients (group 3) averaged 41.30 ± 13.01 (P = 0.33) years. Serum Vitamin D levels were 24.96 ± 9.66 ng/mL in group 1 and 27.70 ± 12.28 ng/mL in group 3, showing no significant correlation with ulcerative colitis (P = 0.41). All groups had a BMI within the normal range, and mean CRP levels varied significantly across groups. Hemoglobin was significantly lower in group 3 compared to group 1 (P = 0.029), but ESR results showed no significant relationship with ulcerative colitis. Vitamin D levels were highest in patients with lower BMI, and no significant relationships were found between Vitamin D and other risk factors, although extensive colitis was associated with higher Vitamin D levels compared to distal colitis.

In this study, there was no significant association between ulcerative colitis and serum levels of vitamin D. However, the small number of patients may limit the conclusions that can be drawn regarding the role of vitamin D in the treatment of ulcerative colitis. Future studies should aim for larger cohorts to provide more definitive insights into this important issue.