Comparison of Absorption of Vitamin D in Cystic Fibrosis

The purpose of this study is to see how well two different forms of vitamin D work in Cystic
Fibrosis (CF). Patients with Cystic Fibrosis have a hard time absorbing certain foods and
often have low vitamin D levels. Studies show that vitamin D may help fight infections
common in Cystic Fibrosis. The investigators would like to see if a powder pill form of
vitamin D will work better than a pill mixed with oil. Each person will randomly receive
either a powder pill or an oil based pill. Blood will be tested while during a 3-4 day
hospital stay. The investigators plan to enroll no more than 24 patients with CF from Emory
University Hospital for this study.

Inclusion Criteria:

- Adult CF patients (age >18 years

- Able to tolerate oral medication

- Expected to survive the duration of the study

Exclusion Criteria:

- Inability to obtain or declined informed consent from the subject and/or legally
authorized representative

- History of disorders associated with hypercalcemia

- Current hypercalcemia (albumin-corrected serum calcium >10.8 mg/dL or ionized calcium
>5.2 mg/dL)

- Chronic kidney disease worse than stage III (<60 ml/min), 7) Forced Expiratory Volume
(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 or illicit drug abuse

- too ill to participate in study based on investigator's or study team's opinion

- current enrollment in another intervention trial