Does vitamin D deficiency contribute to higher disease activity in patients with spondyloarthritis?

This study aimed to compare serum vitamin D levels in Spondyloarthritis (SpA) patients and control group and to evaluate the associations between vitamin D and disease activity in SpA patients.

In this study, 86 SpA patients according to the International Criteria and 117 age and sex-matched healthy controls were included. In patients, clinical examination was performed and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) were recorded. Serum 25(OH)D₃ concentration was measured using ELISA kit.

Serum 25(OH)D₃ levels in SpA patients were significantly lower than healthy controls (p < 0.001). Vitamin D deficiency and insufficiency frequency in the SpA group was significantly more than control group (p < 0.001). No significant difference was observed in the activity of SpA in different serum levels of 25(OH)D. Also, no significant correlations were observed between serum 25(OH)D₃ with clinical findings as well as with BASDAI and BASFI (P > 0.05).

Although our study revealed lower serum 25(OH)D₃ levels in SpA patients compared to healthy controls, there were not any significant correlations between its serum levels with severity of disease. However, correction of vitamin D status may be beneficial in controlling inflammation and disease activity.