Objectives and Study: Cystic Fibrosis (CF) is associated with vitamin D deficiency. The North American CF Foundation recently published new guidelines for the treatment of vitamin D deficiency in individuals with CF. The objective of our study was to assess the efficacy of the new guidelines, and to correlate vitamin D levels and pulmonary function and exacerbations.
Methods: Pulmonary function tests and serum concentrations of 25-hydroxyvitamin D [25(OH)D] were measured in CF patients in one CF Center for one year prior to increasing vitamin D dosage and at least one year of follow-up. In addition, Days Of Hospitalization (DOH) and Respiratory Exacerbations (RE) were counted and an average per year (DOHA and REA, respectively) were calculated.
Results: Of the 90 patients in the study, 49 were males (54.4%), 74 had pancreatic insufficiency (82.2%); mean age 18.17 years. The mean serum concentration of vitamin D at baseline was 20.97 ng/ml compared to 25.41 ng/ml at the end of follow-up (p<0.001). The mean DOHA at baseline was 20.00 days per year compared to 19.04 at the end of follow-up (correlation coefficient = -0.484, p<0.001). The mean REA at baseline was 2.79 exacerbations per year compared to 2.15 at the end of follow-up (correlation coefficient = -0.318, p=0.002).
Conclusion: The new guidelines for management of vitamin D deficiency improve vitamin D levels in patients with CF. The increase in vitamin D levels in individuals with CF decreases both respiratory exacerbations and number of days of hospitalization per year.
