Vitamin D for Enhancing the Immune System in Cystic Fibrosis (DISC Study)

Patients with Cystic Fibrosis (CF) have a shorter life span than the general population due to complications with lung infections, which eventually progress to lung failure. New research has suggested that high levels of vitamin D may be protective against lung infections and may promote the action of anti-bacterial proteins needed to ward off infections. Research has also suggested that high vitamin D levels are linked to lower mortality rates; however these hypotheses have not been adequately studied in patients with CF. An investigation of the effects of vitamin D supplementation is of particular interest in this population because patients with CF generally have high rates of vitamin D deficiency. The investigators have preliminary data from a previous study suggesting that vitamin D supplementation in patients with CF lowers markers of inflammation, promotes anti-bacterial proteins, and reduces mortality. In this proposed multi-center study the investigators will examine the effects of a high dose vitamin D supplementation on patients with CF who are admitted to the hospital for lung infection. The investigators will use a randomized, placebo-controlled trial design to determine if mortality and infection rates over 1 year are reduced in patients who receive the high-dose vitamin D supplementation compared to those who receive placebo. The investigators will also determine if vitamin D affects markers of inflammation and anti-bacterial proteins, as well as CF-related clinical outcomes, such as lung function. The investigators plan to recruit 280 adults and adolescents with CF (ages > 16yrs), with approximately 150 subjects recruited at Emory (Emory University Hospital and Children's Healthcare of Atlanta). Participants will initially be seen by the study researchers during the first week of in-patient hospitalization, and they will be followed over the course of one year during their regularly-scheduled out-patient CF clinic visits. The treatment group will receive an initial oral bolus dose of 250,000 IU vitamin D, and at 3 months follow-up they will receive 50,000 IU vitamin D every other week. Current CF Guidelines for vitamin D supplementation recommend a daily intake of 800 IU of vitamin D per day, therefore in addition to the vitamin D or placebo they receive at the beginning of the study and at 3 months, all participants will receive 800 IU of vitamin D daily. If our hypotheses are correct, this study has potential for reducing infection and promoting survival in patients with CF using vitamin D, a relatively inexpensive supplement.

Inclusion criteria

• Adult and adolescent CF patients
• age >16 years
• admitted to the inpatient hospital setting for a pulmonary exacerbation of cystic fibrosis
• enrolled within 72 hours of admission
• able to tolerate oral medications
• expected to survive hospitalization

Exclusion criteria

• Inability to obtain or declined informed consent from the subject and/or legally authorized representative
• History of serum 25(OH)D >55 ng/mL in the past 12 months
• History of serum 25(OH)D <10 ng/mL in the past 12 months
• Current intake of more than 2,000 IU of vitamin D
• intake of 2,000 IU of vitamin D or its equivalent weekly dose (14,000 IU) for more than 1 week at any time within the past 60 days or intake of greater than vitamin D 10,000 IU once at anytime in the past 60 days
• Pregnancy or plans to become pregnant during the course of the study (12 months)
• History of disorders associated with hypercalcemia including parathyroid disease
• Current hypercalcemia (albumin-corrected serum calcium >10.8 mg/dL or ionized calcium >5.2 mg/dL)
• History of nephrolithiasis
• Chronic kidney disease worse than stage III (<60 ml/min)
• Oral or intravenous glucocorticoid use currently or in the past month
• History of lung transplantation or awaiting lung transplant
• patient in hospice care
• FEV1% predicted <20%
• Current significant hepatic dysfunction total bilirubin > 2.5 mg/dL with direct bilirubin > 1.0 mg/dL
• Current use of cytotoxic or immunosuppressive drugs
• History of AIDS
• History of illicit drug abuse (defined as history of enrollment into a drug rehabilitation program or hospital visits due to drug use within the past 3 years or any use of the following drugs in the past 6 months (cocaine, opiates, amphetamines, marijuana) or any positive toxicology screen for (cocaine, opiates, amphetamines, marijuana)
• Previous enrollment in the study
• Current enrollment in another intervention trial
• Too ill to participate in study based on investigator's or study team's opinion