The prevalence of vitamin D insufficiency and deficiency is high in patients with psoriatic arthritis (PsA), according to research findings reported in Arthritis Care & Research, a journal of the American College of Rheumatology. Seasonal variation in vitamin D levels was not observed in patients in southern and northern locations, and no association between disease activity and vitamin D level was found.
Medical evidence shows that vitamin D deficiency is more common in persons who live at higher latitudes during the winter, suggesting that the deficiency is a result of reduced sun exposure, it was noted. In addition, several studies have reported reduced levels of vitamin D in patients with autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and scleroderma. The investigators suggested that additional research is needed to determine whether patients with PsA require a greater vitamin D intake to maintain healthy levels than that recommended for the general population.