The Effect of Vitamin D Level on Systemic Lupus Erythematosus in Saudi Patients at a Tertiary Care Center

Objective: To assess the prevalence of insufficiency and deficiency of vitamin D, the correlation between vitamin D and disease activity and clinical parameters, and the effect of vitamin D supplementation on SLE activity. Methods: This retrospective study was carried out on 68 Saudi patients aged 15–57 and both sexes who received SLE treatment and met at least four of the 1997-revised classification criteria for SLE as outlined by the American College of Rheumatology. The Abcam ELISA kit catalog ab213966 was employed to quantify serum 25-hydroxycholecalciferol vitamin D (25(OH)D). Results: Post-treatment, SLEDAI score, ESR, bilirubin, and ALP significantly decreased, while RBCs, albumin, vitamin D, and Ca significantly increased. The prevalence of vitamin D insufficiency (45.6%) and deficiency (26.5%) pretreatment decreased to 13.2% and 7.4%, respectively, post-treatment. Pretreatment, vitamin D showed a significant inverse correlation with WBCs, ESR, ALP, and SLEDAI score, and a positive correlation with albumin and Ca. Post-treatment, vitamin D maintained a significant inverse correlation with bilirubin, ESR, ALP, and SLEDAI score and a positive correlation with albumin and Ca. Conclusions: Vitamin D correlated with bilirubin, ESR, ALP, albumin, and Ca. Deficiency is linked to high SLE activity; supplementation reduces it.