Omega-3 Fatty Acids in Rheumatic Diseases: A Critical Review.

Many clinical trials of omega-3 fatty acids, supplied as fish oil supplements, have been carried out in rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), lupus nephritis, and osteoarthritis (OA) over the past 3 decades. This review attempts to summarize the highlights of these studies to evaluate the clinical efficacy for omega-3 fatty acids to be added alongside existing treatment regimens. A total of 20 clinical trials have been carried out in RA, of which 16 exhibited significant improvements in multiple disease clinical outcomes. Nine clinical trials have been completed in SLE and lupus nephritis, of which 6 exhibited significant improvements in 1 or more clinical outcomes. A total of 4 clinical trials have been conducted in OA, of which 3 exhibited significant improvements in at least 1 clinical parameter. Multiple mechanisms for the clinical effects of omega-3 fatty acids have been implicated, including the modulation of eicosanoid synthesis toward a more anti-inflammatory profile and suppressed production of proinflammatory cytokines. Overall, fish oil supplements appear to be a safe and effective agent that could be added to the current treatment regimens in RA. Longer-term trials with larger patient cohort sizes are warranted to establish any long-term benefits of fish oil supplements in SLE, lupus nephritis, and OA.

Vitamin D deficiency in patients with intestinal malabsorption syndromes--think in and outside the gut.

There is a very high prevalence of vitamin D deficiency, which is defined by a serum level of 25-hydroxyvitamin D [25(OH)D] of lower than 20 ng/mL, in all populations of the world. Unfortunately, the prevalence of vitamin D deficiency in patients with intestinal malabsorption syndromes, including cystic fibrosis (CF), celiac disease (CD), short bowel syndrome and inflammatory bowel disease (IBD), is higher than that in the general population, indicating the presence of disease-specific causative factors. In this review, we aimed to present clinical findings to highlight the roles of insufficient exposure to sunlight and inflammation in the development of vitamin D deficiency in patients with intestinal malabsorption syndromes. Furthermore, we aimed to present experimental evidence that supported a role of vitamin D deficiency in the pathogenesis of IBD. Finally, we reviewed clinical intervention strategies aiming to normalize vitamin D status in and even to improve the conditions of patients and to discuss certain issues that needed to be addressed in future research.