Increased Vitamin D Reduces Pulmonary Exacerbations in CF

Increasing Vitamin D Serum Levels Reduces Pulmonary Exacerbations in Patients With Cystic Fibrosis

The investigators study is designed to test the hypothesis that correction of vitamin D in CF patients can increase their lung function and decrease the number of their pulmonary exacerbations.

Vitamin D deficiency is a known problem in CF patients. The CF Foundation Committee published in April 2012 new guidelines for administering vitamin D in CF patients. The investigators' study is designed to look for association between normal serum vitamin D levels and lung function. ~100 CF patients from The Center of Chronic Diseases in Hadassah Medical Organization will be treated according to the new guidelines, and their lung function will be tested once a month during the trial, which will be held for at least one year. In this study, the investigators' goal is to test the efficiency of the new guidelines in correcting serum vitamin D levels, and to follow other related factors such as growth indices (height, weight, BMI), bone mineral density, number of pulmonary exacerbations and number of hospital admissions.

Inclusion Criteria:

• Clinical and laboratory diagnosis of Cystic Fibrosis
• Complete medical and nutritional follow-up for at least one year before changing the vitamin D dosage and follow up for at least one year afterwards.

Exclusion Criteria:

• Age under 4 years old (because of the inability to assess lung function in a reliable fashion)