Vitamin D Levels and Disease Status in Texas Patients With Systemic Lupus Erythematosus

Approximately 65% of the patients with lupus had values less than 80 nmol, which is accepted as the lower limit of vitamin D adequacy. In addition, 20% of the subjects had levels of 25-hydroxyvitamin D that were lower than the normal range for the assay (< 47.7 nmol/L). The group of patients with these lowest levels showed disease activity measures, including global assessment scores, that were higher in the than in those with levels considered normal in the assay (P ≤ 0.003). However, levels of autoantibodies including dsDNA were higher in the group with levels of vitamin D that were greater than 47.7 nmol/L (P = 0.0069). The increased disease symptoms present in patients with very low levels of vitamin D suggests a role for supplementation with exogenous vitamin D to optimize therapeutic outcomes. However, the possibility that such treatment could lead to increased autoantibody levels requires further study.