Associations between vitamin D, bone mineral density, and the course of inflammatory bowel disease in Polish patients

Abstract

INTRODUCTION There are various factors contributing to the pathogenesis of osteoporosis in inflamma‑ tory bowel disease (IBD), including steroid therapy, malnutrition, and vitamin D deficiency. OBJECTIVES The study aimed to assess the vitamin D level among IBD patients and to investigate the relationship between vitamin D concentration and bone mineral density (BMD). PATIENTS AND METHODS The study participants included 239 adult patients with IBD and a control group of 45 healthy adults. Densitometric measurements of the lumbar spine (L1–L4) and femoral neck (FN) were conducted using dual‑energy X‑ray absorptiometry. All patients completed a questionnaire referring to vitamin D supplementation. RESULTS Significant differences were observed with regard to the body mass, body mass index, BMD, the Z‑score, and the T‑score of the FN and L1–L4. Only approximately 25% of all participants presented optimal or high concentrations of vitamin D. The research revealed no differences in vitamin D levels with regard to the disease extent and severity among the patients with ulcerative colitis. No differences were observed in terms of the disease localization, behavior, and the patient age at the time of diagnosis in the patients with Crohn disease. Furthermore, no differences were found in BMD, T‑score, and Z‑score of the FN and L1–L4 between the group of patients who supplemented and did not supplement vitamin D. CONCLUSIONS Vitamin D may not be the only factor affecting BMD. Patients with IBD should supplement a higher dose of vitamin D than healthy adults.