RESUMO
OBJECTIVE: Evaluate the influence of the BsmI polymorphism of the vitamin D receptor gene on vitamin D levels, and inflammatory and oxidative stress markers in patients with Cystic Fibrosis supplemented with cholecalciferol megadose. METHODS: We performed a single-arm, non-randomized pre- and post-study of 17 patients aged 5 to 20 years with cystic fibrosis diagnosed with vitamin D insufficiency/deficiency 25-hydroxy vitamin< 30 ng/mL. Individuals were genotyped for the BsmI polymorphism of the vitamin D receptor gene and all received cholecalciferol supplementation of 4,000 IU daily for children aged 5 to 10 years and 10,000 IU for children over 10 years of age for 8 weeks. Interviews were conducted with personal data, sun exposure, anthropometric and blood samples of 25-hydroxy vitamin parathormone, serum calcium, ultrasensitive C-reactive protein, alpha 1 acid glycoprotein, total antioxidant capacity, malondialdehyde and kidney and liver function. Inter- and intra-group assessment was assessed by paired t-test Anova test or its non-parametric counterparts. RESULTS: The individuals were mostly male and reported no adverse effects from the use of supplementation, 64 % had 25-hydroxy vitamin levels >30 ng/mL. Patients with BB and Bb genotypes showed increased serum levels of 25-hydroxy vitamin. The group with BB genotype showed a reduction in alpha 1 acid glycoprotein. And individuals with the bb genotype had high levels of malondialdehyde compared to the pre-intervention time. CONCLUSION: It is concluded that variations of the BsmI polymorphism of the vitamin D receptor gene have different responses in vitamin D levels and markers of inflammation and oxidative stress.