Wendy A. Hermes, Georgia State University
Date of Award Summer 7-2-2015, Degree Type Thesis, Degree Name Master of Science (MS), Department Nutrition
Background: Despite the high prevalence of vitamin D deficiency in cystic fibrosis (CF) populations, there is little consensus on the most efficacious vehicle substance for vitamin D supplements. Given the high prevalence of pancreatic insufficiency in CF, it is possible that resulting fat malabsorption may impede the ability of patients with CF to absorb vitamin D in an oil vehicle. Further investigation is needed to determine the optimal vehicle substance for use in vitamin D supplements. The objective of this pilot study was to compare the absorption of vitamin D3 and to evaluate the rise in serum cholecalciferol (D3) concentrations in response to vitamin D supplements contained in power or oil vehicles. We hypothesized that vitamin D contained in a powder vehicle would be absorbed more efficiently than vitamin D contained in an oil vehicle in patients with CF.
Methods: This was a double blind, randomized control trial conducted in adult patients with CF during a hospitalization for at least 72 hours at Emory University Hospital for an acute CF event. This study was approved by Emory IRB. All subjects gave written informed consent for participation. Eligible subjects included adults with CF over the age of 18. Subjects were excluded on the basis of a history of hypercalciemia, chronic kidney disease (stage 3 or higher), FEV1%2.5 mg/dL, direct bilirubin > 1.0 mg/dL). Subjects were randomized to either a onetime bolus dose of 100,000 IU of vitamin D contained in a powder (BioTech Pharmacal Inc., 50,000IU/tablet, inactive ingredients gelatin: lactose, cellulose and magnesium stearate) or oil-based vehicle substance (Pro-Pharma, LLC ,10,000 IU/tablet, refined soybean oil and glycerin). Serum D3 concentrations were analyzed at baseline, 12, 24, and 48 hours post-treatment and serum 25(OH)D3 was measured at baseline, 12, and 24 hours. Group differences were assessed with repeated measures ANOVA. The area under the curve (AUC) for serum D3 and the individual 12-hr time-point were also assessed as indicators of D3 absorption in group comparisons (Student’s t-test).
Results: This trial was completed by 16 subjects with CF. The mean age, BMI, and FEV1% were 26.2±6.8 yrs., 20.4± 2.4 kg/m2, 63±17%, respectively. The increase in serum vitamin D3 concentrations was greater in the powder group (pgroup*time