The potential role of vitamin D on disease susceptibility, activity and severity has been considered for several autoimmune rheumatologic diseases include systemic lupus erythematosus (SLE) . Although, there are few studies of vitamin D supplementation in SLE patients, especially in Juvenile Onset Systemic Lupus Erythematosus (JoSLE).

The objective of this study is to evaluate the effect of vitamin D supplementation (cholecalciferol 50.000 international units (IU)/week for 24 weeks) on disease activity (clinical and laboratory parameters), fatigue and bone mass.

This is a study 24-week, two arm, double blinded randomized clinical trial to evaluate the effects of high-dose vitamin D3 supplementation compared with placebo, on activity disease, fatigue and bone mass.

Sixty JoSLE patients will be randomized to receive placebo or vitamin D3 (50.000 IU/week) for 24weeks. The patients return to visits in week 12 and week 24 for evaluation. Study will record clinical history, drugs in use, disease activity, and bone mass parameters.

Inclusion Criteria:

• Written informed consent signed
• 4 of the 11 modified American College of Rheumatology (ACR) Revised Criteria for the Classification of Systemic Lupus Erythematosus .
• SLEDAI < 8 at Screening and at Baseline
• Stable immunosuppressive dose prior to randomization.
• Body Mass Index < 30
• Able to swallow pills at randomization

Exclusion Criteria:

• Refuse of the patient or the legal responsible
• Use of vitamin D2 or D3 supplementation
• Significant renal insufficiency
• Primary hyperparathyroidism (known)
• History of nephrolithiasis (known)
• Diabetes mellitus requiring insulin therapy
• History of vertebral compression fractures (known)
• Pregnancy
• Use of bisphosphonates