Safety and efficacy of a new supplementation protocol in patients with cystic fibrosis and vitamin D deficiency.

OBJECTIVES: Based on the European and American Cystic Fibrosis (CF) consensus recommendations, an increase in vitamin D (VD) supplementation in patients with CF and insufficient or defficient levels was proposed. The objective of our study was to determine the safety and efficacy of this new protocol. MATERIAL AND METHODS: Multicentre nonrandomized uncontrolled experimental study. Patients with insufficient levels (<30 ng/mL) received increasing doses of VD (between 800 and 10 000 IU/day). Patients were followed up for 12 months, during which their vitamin and nutritional status, pulmonary function and calcium and phosphate metabolism were assessed. STATISTICAL ANALYSIS: t test for paired data and multivariate logistic regression analysis. RESULTS: Thirty patients aged 1-39 years (median, 9.1) completed the follow-up. Two patients were dropped from the study on account of 25-OH VD levels greater than 100 ng/mL at 3 months without clinical or laboratory signs of hypercalcaemia. At 12 months, we observed an increase of 7.6 ng/mL (95% CI, 4.6-10 ng/mL) in the mean 25-OH VD level and an improvement in vitamin status: 37% achieved levels of 30 ng/mL or greater, 50% levels between 20 and 30 ng/mL and 13% remained with levels of less than 20 ng/mL. We found no association between improved VD levels and pulmonary function. CONCLUSIONS: The proposed protocol achieved an increase in serum VD levels and a decrease in the percentage of patients with VD insufficiency, although it was still far from reaching the percentages of sufficiency recommended for this entity.

Vitamin D Status in Pediatric and Young Adult Cystic Fibrosis Patients. Are the New Recommendations Effective?

INTRODUCTION: In recent years, guidelines for vitamin D supplementation have been updated and prophylactic recommended doses have been increased in patients with cystic fibrosis (CF). OBJECTIVE: To evaluate safety and efficacy of these new recommendations. RESULTS: Two cohorts of pancreatic insufficient CF patients were compared before (cohort 1: 179 patients) and after (cohort 2: 71 patients) American CF Foundation and European CF Society recommendations were published. Cohort 2 patients received higher Vitamin D doses: 1509 (1306-1711 95% CI) vs 1084 (983-1184 95% CI) IU/Day (p < 0.001), had higher 25 OH vitamin D levels: 30.6 (27.9-33.26 95% CI) vs. 27.4 (25.9-28.8 95% CI) ng/mL (p = 0.028), and had a lower prevalence of insufficient vitamin D levels (<30 ng/mL): 48% vs 65% (p = 0.011). Adjusted by confounding factors, patients in cohort 1 had a higher risk of vitamin D insufficiency: OR 2.23 (1.09-4.57 95% CI) (p = 0.028). CONCLUSION: After the implementation of new guidelines, CF patients received higher doses of vitamin D and a risk of vitamin D insufficiency decreased. Despite this, almost a third of CF patients still do not reach sufficient serum calcidiol levels.