@article{perez_oliveira_levy-neto_caparbo_pereira_2017,  title={Serum 25-hydroxyvitamin D levels in patients with Granulomatosis with Polyangiitis: association with respiratory infection},  volume={72},  ISSN={1807-5932},  url={https://doi.org/10.6061/clinics/2017(12)02},  DOI={10.6061/clinics/2017(12)02},  number={12},  journal={Clinics},  publisher={Faculdade de Medicina / USP},  author={Perez, Mariana O. and Oliveira, Ricardo M. and Levy-Neto, Mauricio and Caparbo, Valeria F. and Pereira, Rosa M.R.},  year={2017},  month={Dec},  pages={723–728} }