Vitamin D deficiency in Saudi patients with systemic lupus erythematosus

Objectives: To determine vitamin D status among Saudi patients with systemic lupus erythematosus (SLE) versus matched control group. Methods: Hospital-based cohorts of 165 SLE patients and 214 SLE-free volunteers were recruited at King Abdulaziz University Hospital in Jeddah, Kingdom of Saudi Arabia between January 2006 and June 2008. Serum levels of 25-hydroxyvitamin D [25(OH)D] were measured. Vitamin D sufficiency is defined as a serum level of 25(OH)D >= 75nmol/L (>= 30ng/ml). A level ranging between >50 to <75nmol/L (>20 to <30ng/ml) is considered as vitamin D insufficiency, whereas <= 50nmol/L (520ng/ml) as vitamin D deficiency. Both deficiency and insufficiency are considered to comprise vitamin D inadequacy. Results: The prevalence of SLE patients with 25(OH) D inadequacy and deficiency was higher than in the control group: 98.8 versus 55%, 89.7 versus 20% (p<0.0001). Only 2 (1.2%) SLE patients had adequate levels of 25(OH)D compared to 96 (45%) of control group (p<0.0001). The mean serum levels (nmol/L) of 25(OH)D in SLE patients with vitamin D inadequacy and deficiency in comparison to the control group were 22.3 +/- 13.6 versus 44.5 +/- 17.5 (p<0.0001) and 19.1 +/- 9.5 versus 22.9 +/- 6.7 (p=0.0152). No significant differences were evident in female and male patients with SLE with respect to the mean serum levels of 25(OH)D and prevalence of its deficiency. Conclusion: Vitamin D inadequacy is highly prevalent in Saudi patients with SLE. Vitamin D supplementation and its evaluation in the treatment of SLE should be considered.