Efficacy of Intensive Cholecalciferol Monitoring and Supplementation on Serum vitD Levels in Pediatric Patients With CF

Randomized double-blind clinical trial in patients aged 5 to 18 years attending the CF Comprehensive Care clinic in Mexico City. The intervention group will receive an intensification of vitamin D supplementation, with increments of 4000 IU depending on serum levels, the control group will receive supplementation according to the treatment guidelines of the Cystic Fibrosis Foundation, and the dose will be doubled depending on serum levels. In both groups vitamin D levels will be measured at 3, 6, 9, and 12 months, spirometry and sputum culture will also be performed to evaluate the pulmonary function, densitometry to evaluate the bone mineral density and body composition, together with anthropometric evaluation and quantitative bone ultrasound at each visit, in the biochemical evaluation, calcium/creatinine ratio and alkaline phosphatase will be taken at each visit.