Efficacy of Vitamin D3 for the Treatment of Psoriatic Patients With Vitamin D Deficiency and Insufficiency

Inclusion Criteria: * Mild to moderately severe (PASI ≤ 10), chronic plaque type psoriasis vulgaris patient, who is a new case or has at least treatment-free period as following: 4 weeks for topical calcipotriol, topical corticosteroid or 8 weeks for systemic therapy (i.e. cyclosporine, acitretin, methotrexate) or 12 weeks for Psoralen Ultraviolet A (PUVA), phototherapy or biological treatment. * Age 18-year-old to 70-year-old. * Psoriasis vulgaris patient with vitamin D insufficiency or deficiency. Exclusion Criteria: * Pregnancy or Lactating mother. * Subject with history of major gastrointestinal surgery or gastric bypass surgery. * Subject with history of pustular psoriasis. * Subject with active psoriatic arthritis. * Subject with prior phototherapy within the past 3 months. * Subject with history of hypocholesterolemia (serum cholesterol \< 120 mg/dl) or primary hyperparathyroidism. * Subject who regularly takes vitamin D supplement exceed 3,000 iu/day and high vitamin D diet, for example cod liver oil. * Subject with liver disease, cystic fibrosis, Crohn's disease, celiac sprue, renal disease, pancreatic disease, and inflammatory bowel disease. * Subject taking following medication: corticosteroid, orlistat, rifampicin, isoniazid, ketoconazole, statin, and cholestyramine.