Vitamin D deficiency among Jordanian university students and employees

This paper aims to assess the prevalence of vitamin D deficiency among female university students and employees at the Hashemite University (HU) and, then, to identify risk factors for developing vitamin D deficiency among this population. Vitamin D deficiency remains widespread in many countries, including Jordan, and has been linked to many diseases.

In this cross-sectional study, blood samples were taken from 320 healthy females – 160 students and 160 employees – aged between 18 and 65 years old who presented for routine checkup at the medical center of HU. Level of direct sun exposure and barriers to getting enough sunlight (dress style, skin color and sunscreen use) were questioned. Serum levels of 25-hydroxyvitamin D were measured, and the daily intakes of vitamin D, calcium and phosphorous were estimated through completing an adopted food frequency questionnaire. All required data were collected using a face-to-face interview by trained dietitians. The software package ESHA was used to determine the daily intake from the nutrients.

The prevalence of vitamin D deficiency (25-OHD < 25 nmol/L) was 31.2 per cent in female students compared to 20.5 per cent in female employees. Prolonged exposure to sun was independently related to vitamin D deficiency (odds ratio = 4.55); participants exposed for 30 minutes daily were at a higher risk for vitamin D deficiency. However, estimated vitamin D intake was not affected by age and working status.

The present study has some important limitations. First, this study based on serum 25-OHD results, which alone, without biochemical parameters such as parathyroid hormone (either primary or secondary), might be linked to accelerated degradation of 25-OHD and shorter half-life. Second, the half-life of 25-OHD was not consistently available. Third, the smaller sample size of participants. Finally, the present study did not distinguish between intake of vitamin D2 and D3. This limitation caused the inability to precisely evaluate the prevalence of vitamin D deficiency in the studied population.

This study indicates that it is crucial to create awareness concerning the daily intake of vitamin D in the community to avoid long-term complications related to vitamin D deficiency, by using urgent measures including vitamin D supplementation and fortification of some highly consumed food, milk and other dairy products. Educational endeavors about sensible sun exposure should be implemented to improve vitamin D status among this population. The findings of the present study call for action at the national level to build strategies for health promotion about vitamin D supplementation in groups at risk for low supplementation (e.g. younger female students, with previous chronic diseases and poor sun exposure), and engage these populations in strategizing for successful and demographically relevant outreach and education in their own communities along with effort to prevent obesity and diabetes as well as raising awareness through simple programs to prevent and treat vitamin D deficiency among women living in Jordan.

The high prevalence of vitamin D deficiency among female university students in this study emphasizes the necessity of vitamin D supplementation and calls for action to build strategies for health promotion concerning vitamin D supplementation.