CHINESE MEDICAL JOURNAL, cilt.125, sa.14, ss.2511-2515, 2012 (SCI-Expanded)
Background Vitamin D has been found to have a role in the function of the immune system. There have been a lot of studies investigating a relation between vitamin D and disease activity in ankylosing spondylitis (AS). However, there have not been any studies arranging AS in groups according to vitamin D levels and determining any differences among these patients in terms of disease activity, functional status, quality of life, and other clinical parameters. The aim of this study is to compare 25-hydroxy-vitamin D3 (25(OH)D3) levels in AS patients with those in normal healthy subjects and to determine the relationship between 25(OH)D3 levels and AS disease activity, functional status, and quality of life.