Background/Aims: Vitamin D deficiency is highly prevalent worldwide and has been linked to many diseases. The aims of the present study were to assess the vitamin D status of Jordanians at the national level and to identify groups of the population at high risk for vitamin D deficiency. Methods: Vitamin D status was assessed in a national sample of 5,640 subjects aged ≧7 years. The study involved interviews, laboratory measurements of 25(OH)D and others, and physical measurements. The present report deals, exclusively, with subjects aged >18 years. Results: The prevalence of low vitamin D status [25(OH)D <30 ng/ml] was 37.3% in females compared to 5.1% in males. Dress style in females was independently related to low vitamin D status; women wearing ‘Hijab’ (adjusted OR = 1.7, p = 0.004) or ‘Niqab’ (adjusted OR = 1.5, p = 0.061) were at a higher risk for low vitamin D status than were western-dressed women. Conclusion: The high prevalence of low vitamin D status in females in contrast with a low prevalence in males, together with a higher prevalence in women wearing Hijab or Neqab, calls for action to increase the population’s awareness and to develop strategies to reduce this risk among women, particularly those wearing dress styles that cover most or all of their skin.