Study of biochemical profile and 25-hydroxy Vitamin D association with disease activity in rheumatoid arthritis patients

BACKGROUND: Vitamin D deficiency has been implicated in the pathogenesis of autoimmune diseases. Reduced Vitamin D intake has been linked to increased susceptibility to the development of rheumatoid arthritis (RA). The objective was to evaluate 25-hydroxy (25-OH) Vitamin D status in patients with RA and to assess the relationship between Vitamin D level and RA disease activity. MATERIALS AND METHODS: The study consists of 50 RA patients as cases and 50 age- and body mass index matched healthy individuals as controls. All study participants (both controls and cases) underwent biochemical profile such as RA factor, serum uric acid (UA), calcium, phosphorous, alkaline phosphatase, and 25-OH Vitamin D levels. Disease activity was evaluated by calculating the 28-joint count as disease activity score. All the results were expressed as mean and standard deviation (SD). RESULTS: Mean and SD values of serum UA (mg/dl), calcium (mg/dl), and phosphorous levels (mg/dl) in RA cases are as follows 7.2 ± 1.3, 7.5 ± 0.5, and 6.9 ± 1.5, respectively. Serum UA, calcium, and phosphorous levels in RA cases were found to be elevated when compared to controls (P < 0.0001). Mean erythrocyte sedimentation rate was 58.4 ± 14.7 mm/h in the group of patients with RA. Levels of 25-OH Vitamin D were found to be negatively correlated to the DAS28, the correlation coefficient being r = −0.51 (P < 0.05). Levels of 25-OH Vitamin D were found to be positively correlated to serum calcium levels, the correlation coefficient being r = 0.82 (P < 0.01). CONCLUSION: RA patients had lower Vitamin D values than healthy controls. There was a negative correlation between serum Vitamin D and RA disease activity.