However, it is not well documented in our country, especially in the inpatients with chronic diseases. Aims: This study sought to investigate the vitamin D status in the inpatients in Rheumatology Department of Cho Ray Hospital and to examine the characteristic of vitamin D deficiency distribution. Methods: The study was designed as cases study which involved 324 patients (216 women and 109 men) aged between 14 and 96 years who had been hospitalized in the Rheumatology Department, Cho Ray hospital, Ho Chi Minh City between Feb 2010 and Jun 2010.