Background: Vitamin D deficiency has been linked to increased susceptibility to the development of rheumatoid arthritis (RA) and may be associated with disease activity in patients with RA. Vitamin D deficiency is common in healthy Saudi Arabian women. The objective of this study was to evaluate vitamin D status in patients with RA and to assess the relationship between vitamin D levels and disease activity in adult Saudi Arabian women. Subjects and method: This study was conducted at King Saud Hospital, AL-Qassem area, Saudi Arabia between January 2012 and May 2013 and had been carried out on 40 patients diagnosed as having RA and 40 healthy adult females matched for age as a control group. All participants were subjected to full history taking, clinical examination, laboratory investigations including assessment of serum calcium, serum phosphorus, and 25-hydroxy vitamin D3 (25(OH)D3). Disease activity of RA was assessed using Disease Activity Score Index of a 28 joint count (DAS28), CRP and ESR.
Results: There was a highly significant difference between RA patients and healthy controls as regarding the mean 25(OH)D3 (10.8±4.8 vs 19±7.96 ng/ml; p< 0.001) and both were below the reference range . We found that 25(OH)D3 was not correlated with DAS28, the correlation coefficient being -0.14, and was also not correlated with CRP or ESR in RA patients.
Conclusion: Vitamin D deficiency is prevalent in healthy Saudi women and highly prevalent in Saudi women with RA, but vitamin D deficiency is not linked to disease activity in RA. These results may raise our important rationale for vitamin D supplementation to decrease the risk of development of rheumatoid arthritis, but more definitive evidence is also required to demonstrate the clinical benefit of vitamin D supplementation in the treatment of RA.