Background and aims Vitamin D has important role in the regulation of the immune system in Lupus. 71% of lupus patients in Indonesia experienced hypovitamin D. This study was aimed to determine the effect of vitamin D supplementation on the levels of anti ds dna and degree of urine protein in lupus patients with hypovitamin D.

Methods Thirty nine SLE patients with hypovitamin D were studied, that randomzed into two groups: 20 patients was given vitamin D and 19 patients received placebo for 3 months. Anti-ds DNA levels were measured by ELISA and urine protein were measured by dipstick method.

Results Anti-dsDNA levels in the supplement group before and after giving vitamin D were 226.84±82.11 vs 191±72.55 (p=0.00), and the placebo group were 233.69±66.52 vs 227.72±61.21 (p=0.077). The degrees of urine protein in the supplement group before and after treatment were 24 vs 12 U/ml (p=0.003) and the placebo group were 16 vs 10 U/ml (p=0.070).

Conclusions Vitamin D supplementation plays a role on decreasing the levels of anti ds-DNA and urine protein in SLE patients with hypovitamin D.