The purpose of the study is to test the clinical efficacy of oral Vitamin D3 on Wound Healing in patients with Chronic Rhinosinusitis With Nasal Polyposis and Lower Vitamin D Levels After Endonasal Endoscopic Sinus Surgery

Inclusion Criteria:

• 1. Clinical diagnosis of Chronic Rhinosinusitis with nasal polyps 2. Be 18-60 years old of Chinese people and of either sex，the Han nationality 3. Vitamin D level of less than 30 ng/ml

Exclusion Criteria:

• 1. Women must not be pregnant, breast feeding 2. Chronic oral corticosteroid therapy 3. History of physician-diagnosed nephrolithiasis 4. Chronic diseases（ diabetes，Hypertension，renal insufficiency, severe liver disease） 5.prior surgeries of the paranasal sinuses 6. With an upper respiratory tract infection within 4 weeks of entering the study