In a recent paper titled “Vitamin D deficiency in chronic inflammatory rheumatic diseases: results of the cardiovascular in rheumatology [CARMA] study“, published in Arthritis Research & Therapy, researchers showed new evidence associating chronic inflammatory rheumatic diseases (CIRD) to vitamin D deficiency in patients suffering from some types of arthritis.
CIRD can be defined as an inflammatory medical condition affecting the location at which bones (joints)/ tissues connect. According to the American College of Rheumatology, CIRD represents the second most common cause of disability after musculoskeletal injuries. Basically, CIRD is a general term utilized to describe over 100 conditions, including several types of arthritis, such as rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Depending on the condition, patients with arthritis suffer from chronic pain due to swollen, stiffness joints and inflamed connective tissues like cartilage and tendons.
Although the exact causes of the disease are unknown, CIRD is generally assumed to be linked to an autoimmune response. This means that the body’s immune system attacks its own cells, leading to inflammation. Some studies suggest the link between increased autoimmune diseases and vitamin D deficiency, though it is not clear whether this constitutes the cause or effect of the inflammatory process.
In this study, a total of 2,234 patients suffering from various types of arthritis were assessed, including 775 RA, 738 AS and 721 PsA. Also, over 677 non-CIRD subjects were used as controls. It is worth noting that deficiency is recorded when the concentration of vitamin D is below 20 nano-grams/ milliliter.
The results showed that 40.5 % RA, 39.7 % AS, 40.9 % PsA and 26.7 % non-CIRD controls had signs of vitamin D deficiency. After statistical analysis of the data, a very good correlation was established between patients with RA and vitamin D deficiency. By contrast, no significant positive association between AS patients and vitamin D deficiency was established. Finally, a slightly significant correlation between disease activity/severity and vitamin D deficiency was also recorded.
This study shed new insights on the impact of vitamin D deficiency in patients with CIRD and these results might be of considerable interest in future daily clinical practice. In spite of lower disease activity, patients with RA have considerable risk of vitamin D deficiency. Hence, monitoring levels of vitamin D in these patients is an important issue, which can be managed by administrating vitamin D supplements or extended exposure to sunlight if available.