BackgroundVitamin D, or the “sunshine” hormone became an attractable topic that recently captivates many researchers. The increased prevalence of vitamin D deficiency became an alarming health concern despite the accumulative evidence exploring its crucial role not only in bone metabolism, but also in a variety of pleiotropic functions throughout the various body organs. The aim of this study is to compare the prevalence that might influence vitamin D deficiency among Saudi and non-Saudi nationalities in Almadinah Almunawarh, Saudi Arabia, and to study the different factors that may have an influence in the difference of this prevalence like the marital status, occupation, smoking, sunlight exposure, education, and dietary habits.MethodsThe study was a cross sectional study done in the medical care unit in Taiba University Almadina Almunawarah in which, 65 healthy male individuals from different nationalities (Saudis and non-Saudis), aged 18 - 65 years were divided into 2 groups, 33 Saudis and 32 non-Saudis. A sociodemographic questionnaire was filled by the study participants and 25-OH vitamin D3 (25(OH)D3) concentrations were detected by electrochemiluminescence immunoassay.ResultsResults showed a Significant percentage of the participants in the Saudi group (n = 30, 91%) suffered from deficiency in vitamin D levels [25 (OH) D < 20 ng/ml] 12.57 ± 4.82 (mean ± SD), compared to only 47% (n = 15) in the non-Saudi group [21.56 ± 6.82 (mean ± SD)]. Vitamin D deficiency was found to be significantly higher in the Saudi group than the non-Saudi group with P = 0.001.ConclusionResults showed a significant increase in vitamin D deficiency in Saudi population than the non-Saudis P = 0.001. The occupation status was found to be the only factor positively correlated with vitamin D deficiency.