Effects of an Antioxidant-Enriched Multivitamin Supplement on Inflammation and Oxidative Stress in Cystic Fibrosis

Inclusion Criteria: * Male or female ≥10 years of age * Documentation of a Cystic Fibrosis (CF) diagnosis as evidenced by 1 or more clinical features consistent with the CF phenotype and 1 or more of the following criteria: * Sweat chloride equal to or greater than 60 milliequivalent (mEq/L) by quantitative pilocarpine iontophoresis test (QPIT) * 2 well-characterized mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene * Pancreatic insufficiency documented by having a spot fecal elastase-1 (FE-1) ≤ 100μg/g in a stool sample done either historically or at the screening visit * Clinically stable with no significant changes in health status within 2 weeks prior to randomization * Forced expiratory volume over one second (FEV1) ≥ 40 and ≤ 100% of predicted for age based on the Wang (males \< 18 years,females \< 16 years) or Hankinson (males ≥ 18 years, females ≥ 16 years) standardized equations at the screening visit * Weight ≥ 30 kg at the screening visit * Able to perform repeatable, consistent efforts in pulmonary function testing * Able to tolerate sputum induction with 3% hypertonic saline and to expectorate with induction * Written informed consent (and assent when applicable) obtained from subject or subject's legal representative * Ability to swallow softgel capsules Exclusion Criteria: * Subjects being treated with ivacaftor (Kalydeco™) * Liver enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), or gamma-glutamyl transferase (GGT) \> 3 times the upper limits of normal at the screening visit * Use of antibiotics (oral, iv, and/or inhaled) for acute respiratory symptoms within 2 weeks prior to randomization * Active treatment for allergic bronchopulmonary aspergillosis (ABPA) * Current use of oral corticosteroids in doses exceeding the equivalent of 10 mg prednisone/day or 20 mg prednisone every other day * Active treatment for nontuberculous mycobacterial (NTM) infection * Initiation of any new chronic therapy (e.g., ibuprofen, Pulmozyme®, hypertonic saline,azithromycin,Tobramycin Inhalation solution (TOBI®), Cayston® within 8 weeks prior to randomization * Unwilling to discontinue current oral vitamin and antioxidant supplementation (e.g.,AquADEKs®, another source of β-carotene, vitamin A, vitamin E or tocopherols,vitamins D or K, n-acetylcysteine, glutathione, CoQ10, other over-the-counter antioxidant) for the duration of the study * Use of vitamins (other than control vitamin) or antioxidants within 4 weeks prior to randomization * Daily use of \> 2 cans of Boost or Pulmocare dietary supplement formulas * Known hypersensitivity to oral AquADEKs® * For women of child bearing potential: 1. positive pregnancy test at Visit 1 or at Visit 2, or 2. lactating or 3. unwilling to practice a medically acceptable form of contraception (acceptable forms of contraception: abstinence, hormonal birth control, intrauterine device, or barrier method plus a spermicidal agent) * Subject unlikely to complete the study as determined by the Investigator * Any condition that the Investigator believes would interfere with the intent of this study or would make participation not in the best interest of the subject * Use of investigational therapies within 4 weeks prior to randomization * Current tobacco smoker * Current use of anticoagulant medications * Severe malnutrition based either on having a BMI less than the 5th percentile for subjects \< 18 years of age or a body mass index (BMI) less than 18 kg/m2 for subjects \> 18 years of age. * Subjects with poorly controlled CF-related diabetes on active insulin therapy, defined as having a Glycosylated Hemoglobin (HgbA1c) ≥ 7.5% at the most recent historic evaluation of HgbA1c