Effect of Vitamin D Supplement on Disease Activity in SLE

Inclusion Criteria: * Age \> 18 year-old * SLE classified by revised ACR criteria, SLICC 2012 criteria * SLE patients who have mild to moderate disease activity ( clinical SLEDAI-2K 3-10 ) and has vitamin D level \< 40 ng/ml * currently treated with stable dose of 1 or more of the following background medication : NSAIDs, anti-malarial, MMF, Azathioprine, methotrexate, cyclosporin for at least 1 month, corticosteroid \</= 20 mg/d of prednisolone or equivalent dose for at least 2 weeks * received calciferol 20,000 IU/wk (1 cap) at least 12 weeks Exclusion Criteria: * patients with chronic liver disease, CKD stage 3, bed ridden, malignancy * patients who received drug that interfere with vitamin D metabolism * poor drug compliance * overlap with other connective tissue disease or a diagnosis of MCTD * hx of vitamin D allergy * hx on MTV or other supplementation