The Relationship between Serum Level of Vitamin D3 and the Severity of New Onset Rheumatoid Arthritis Activity

Abstract

Introduction: Rheumatoid Arthritis (RA) is a systemic inflammatory disease which typically involves wrists, ankles, and finally every joint. Some of studies have reported a reverse relationship between the level of vitamin D and RA severity. Aim: The present study was carried out in order to check the potential relationship between the level of vitamin D and RA severity. Materials and Methods: Ninety-three patients with RA with onset in recent three months (new onset RA), and 31 patients without RA were chosen as the control group. The patients all aged under 75 years and were diagnosed by a rheumatologist. The serum level of vitamin D was measured through blood test by chemiluminescence method by taking a blood sample of 5 cc. The relationship between the average level of vitamin D and disease severity was analyzed based on scoring scale of DAS28 in different groups with RA. The significant level of the above mentioned tests was set at p<0.05. Data analysis was carried out using SPSS 20.0. Results: The results of the present study indicated that there was no significant relationship between the two groups in terms of the serum level of vitamin D. Since the subgroups of the patients are not homogenous in terms of age and based on disease severity, ANOVA and chi-square were used to modify this heterogeneity and compare vitamin D levels in patients based on disease severity. The results indicated that there was a significant difference between the three groups of patients in terms of disease severity, such that disease severity rose with a decrease in the serum level of vitamin D, (p-value <0.001). Conclusion: There was a significant reverse relationship between the serum level of vitamin D and RA severity based on Das Score 28. Therefore, it is recommended that if there is a lack of or insufficient amounts of this vitamin in the body, vitamin D supply needs to be optimized along with other standard medications in order to reduce the RA severity.

Keywords

• disease severity score
• rheumatoid arthritis severity
• vitamin d