Relationship between Serum Levels of Vitamin D, Calcium and Phosphorus with Disease Severity in Patients with Rheumatoid Arthritis referred to a Military Hospital

Rheumatoid arthritis is a systemic and chronic disease. In this study, we examined the serum levels of vitamin D, calcium and phosphorus in this disease and its relationship with clinical symptoms based on the patient's Disease Activity Score 28 (DAS28).

This prospective cross-sectional study was performed on patients with rheumatoid arthritis referred to the rheumatology clinic of a military hospital in Tehran, Iran. The diagnosis was made by a rheumatologist according to the criteria of the American Rheumatological Association. After admission, the severity of rheumatoid arthritis was assessed according to DAS28 criteria, which is based on the number of painful joints, number of swollen joints, erythrocyte sedimentation rate (ESR) test and Visual Analogue Scale (VAS). Serum levels of vitamin D, calcium and phosphorus were also measured in all of these patients.

one hundred patients were present in this study, of which 22 were male (22%) and 78 were female (78%). The mean age of patients was 53.7±11 years (range: 26-76 years). The mean score of disease severity among patients was 14.4±1.2 (range 1.4-7.6). 12% of patients had passive disease, 8% had low-activity disease, 62% had moderate activity and 18% had severe activity. There was a significant difference between the severity of the disease and serum levels of vitamin D, calcium and phosphorus. Patients with higher disease severity had lower levels of calcium and vitamin D while higher levels of phosphorus (p <0.05).

In patients with active rheumatoid arthritis, serum levels of vitamin D are low, so it is recommended to investigate the effect of this vitamin on improving the severity of the disease in these patients so that the final decision to increase this vitamin to the treatment regimen can be made.