The association between serum vitamin D and inflammatory bowel disease

Patients with inflammatory bowel disease have an increased risk of vitamin D deficiency and this may impact upon the disease activity. This study explored the association between serum vitamin D levels and inflammatory bowel disease in a Chinese population. Sixty-five patients with ulcerative colitis (UC) and 50 with Crohn's disease (CD) were investigated between January 2015 and December 2016 at the Kunshan Second People's Hospital, China. A control group of 120 healthy volunteers was also selected. Serum vitamin D levels were detected and compared between groups and among patients with different disease activity. The serum vitamin D levels in the UC (10.27 ± 4.05 ng/mL) and CD (11.13 ± 3.96 ng/mL) groups were lower than in the control group (12.96 ± 5.18 ng/mL) (P < .05). In the UC group, during the moderate (9.21 ± 3.26 ng/mL) and severe (7.58 ± 3.81 ng/mL) periods, serum vitamin D levels were significantly lower compared with during remission (12.18 ± 3.69 ng/mL) and the mild period (11.35 ± 4.08 ng/mL) (P < .05). In the CD group, serum vitamin D levels were significantly lower during the moderate (10.28 ± 3.57 ng/mL) and severe (8.52 ± 3.72 ng/mL) periods compared with remission (13.97 ± 5.61 ng/mL) (P < .05). Patients with UC and CD are both prone to vitamin D deficiency. Serum vitamin D was significantly lower with aggravating disease status. Therefore, vitamin D may be involved in the development of inflammatory bowel disease in a Chinese population.