Vitamin D levels and their association with oxidative stress and inflammation markers in patients with cystic fibrosis.

Introduction: cystic fibrosis is a disease that causes inflammation, oxidative stress and metabolic changes that lead to nutrient deficiency, such as vitamin D deficiency. On the other hand, it is suggested that vitamin D has anti-inflammatory and antioxidant actions. Objective: to evaluate the prevalence of hypovitaminosis D and the association between serum 25 hydroxyvitamin D levels with markers of oxidative stress and inflammation in patients with cystic fibrosis. Method: a cross-sectional study was carried out with 48 patients with cystic fibrosis including children, adolescents and adults in the northeast region of Brazil. Blood collection was performed for analysis of 25-hydroxyvitamin D, calcium, parathyroid hormone, inflammatory process (C-reactive protein (CRP) and alpha-1-acid glycoprotein-A1 (A1GPA)) and oxidative stress (malondialdehyde (MDA) and total antioxidant capacity (CAOT)). The statistical analysis was performed using the "Statistical Package for the Social Sciences", adopting a significance level of p < 0.05. Results: Vitamin D insufficiency/deficiency was found in 64.6 % of patients. After multiple linear regression analysis, MDA showed an inverse association with blood values of 25-Hydroxyvitamin D (p < 0.05) conditioned by the presence of inflammatory process markers. When only oxidative stress was evaluated, this association disappeared. Conclusion: in conclusion, there was a high prevalence of hypovitaminosis D, with 25(OH)D levels associated with greater oxidative stress when combined with inflammatory markers. Improved vitamin D levels may be an alternative to reduce the damage caused by excess oxidative stress and inflammation in CF patients.