Vitamin D in Systemic Lupus Erythematosus: Modest Association With Disease Activity and the Urine Protein‐to‐Creatinine Ratio

Objective To investigate whether an increase in vitamin D levels in patients with systemic lupus erythematosus (SLE) was associated with improvement in disease activity. Methods A total of 1,006 SLE patients were monitored over 128 weeks. SLE patients with low levels of 25‐hydroxyvitamin D (25[OH]D;