Open-label Vitamin D Trial for Patients With Cystic Fibrosis and Allergic Bronchopulmonary Aspergillosis

Inclusion Criteria

• Male or female ≥ 12 years of age at enrollment
• Confirmed diagnosis of CF based on the following criteria:
• One or more clinical features consistent with the CF phenotype AND (b or c)
• Positive sweat chloride > 60 mEq/liter (by pilocarpine iontophoresis)
• two identifiable mutations consistent with CF
• Written informed consent (and assent when applicable) obtained from subject or subject's legal representative and ability for subject to comply with the requirements of the study.
• Clinically stable at enrollment as assessed by the site investigator
• Past or present respiratory culture positive for Aspergillus fumigatus
• IgE ≥ 250 and/or presence of class II or higher aspergillus specific IgE on enrollment
• Ability to comply with medication use, study visits and study procedures as judged by the site investigator -

Exclusion Criteria

• 1. Systemic corticosteroids (1 mg/kg if 20 mg of prednisone per day),.
• Investigational drug use within 30 days of screening 3. Laboratory abnormalities at screening

a. Serum Calcium > 11 mg/dl b. 25(OH) D > 50 ng/ml at screening. c. Creatinine ≥ 1.5, or estimated GFR <60 by Cockcroft-Gault or MDRD equation. d. LFT≥ 3xULN

• History of transplantation or currently on lung transplant list 5. Positive serum pregnancy test at screening (to be performed on all post-menarche females) 6. Pregnant, breastfeeding, or if post-menarche female, unwilling to practice birth control during participation in the study 7. Presence of a condition or abnormality that in the opinion of the site investigator would compromise the safety of the subject or the quality of the data 8. Diagnosis of HIV and a CD4+ T cell count below 500 cells/ml or active hepatitis B or C infection.
• Undergoing therapy for non-tuberculous mycobacterial infection