Patients hospitalized with COVID-19 have low levels of 25-hydroxyvitamin D
                            
                                                                                                        N. Hutchings,
                                                                                                        V. Babalyan,
                                                                                                        S. Baghdasaryan,
                                                                                                        M. Qefoyan,
                                                                                                        N. Sargsyants,
                                                                                                        E. Aghajanova,
                                                                                                        A. Martirosyan,
                                                                                                        R. Harutyunyan,
                                                                                                        O. Lesnyak,
                                                                                                        A. Formenti,
                                                                                                        A. Giustina,
                                                                                                        J. Bilezikian,
                                                            
                            
                                2021