The prevalence of vitamin D deficiency among female college students at Qatar University.

N vitamin D deficiency is considered a common problem among many Arab countries including Lebanon, Qatar, the Kingdom of Saudi Arabia, United Arab Emirates, and other European countries as documented by many studies.1-4 Vitamin D is a fat-soluble steroid hormone that is crucial for many tissues and organs in the body for instance, skin, heart, kidney, and muscles. Vitamin D deficiency has been shown to play a role in almost every major disease, including: osteoporosis, rickets, and osteopenia, several types of cancer (including breast, prostate, and colon), heart disease, obesity, diabetes, autoimmune diseases, multiple sclerosis, rheumatoid arthritis, hypertension, infertility and postmenaupousal syndrome (PMS), Parkinson’s, depression, Alzheimer’s, and chronic fatigue syndrome.5 Factors that contribute to the deficiency of vitamin D are: limited exposure to sunlight, low dietary intake of foods that contain vitamin D, overdressed, high altitude and cold countries, and skin color.5 In the last few years, vitamin D deficiency has become a common problem among Qatari generations and Qatari residents. Additionally, there is raising awareness that vitamin D adequacy is essential for optimal health. This study is the first to investigate the prevalence of vitamin D among female college students in the state of Qatar. Bener et al2 reported that the prevalence of vitamin D deficiency among Qatari children aged between 11 and 16 years was 68.8%, more among girls (51.4%) than boys (48.6%).2 Another study3 was conducted at the Rheumatology Clinic Practice at Hamad Medical Corporation on 204 health professional females, mean aged 35.9 years. This study showed that 26% of females had vitamin D level below the detection limit (<3 ng/ml), 38% had severe deficiency (vitamin D <10 ng/ml), 25.1% had mild deficiency in vitamin D (<20 ng/ml) and 8.9% had a level below 30 ng/ml, and only 2% had an optimal level of vitamin D (>30 ng/ml).3 To date there is no documented study to assess the vitamin D level among female college students. Therefore, the objective of this study was to define the prevalence of vitamin D insufficiency/deficiency in female college students at Qatar University. The secondary objective was to assess the associations of biochemical, anthropometric, skin color and exposure to sun with the concentration of vitamin D. A cross sectional study was conducted between October and December 2010 on female students at Qatar University, aged between 19-27 years old, in good general health, and selected based on randomized sampling. Subjects were originally from Qatar, Bahrain, Oman, Yemen, Syria, Palestine, Jordan, Egypt, Iran, Pakistan, Sudan, and Eritrea. Most of the study subjects had covered heads and wore clothes with long sleeves. Those who were taking vitamin D, or calcium supplementation, pregnant females, and who had conditions like anemia and kidney disease were excluded from the study. Anthropometric measurements were made and the mean (± SD) body mass index (BMI) was 23.24±4.33 kg/m2, and waist circumference 72.79±9.65 cm. The project was approved by the Institutional Review Board of Qatar University and granted a Research Ethics Review Exemption Approval number (QU-IRB 42-E/10), and all volunteer subjects gave written informed consent. The designed questionnaire included information dealing with the skin color, dietary intake, sun exposure time, and site of body exposed. Analysis of vitamin D, parathyroid hormone, serum alkaline phosphatase, corrected calcium, creatinine, and albumin concentrations were carried out at Hamad Medical Corporation, Doha, Qatar. Data were expressed as mean and standard error for continuous data, and percentages for categorical data. Data was explored for outliers, skewness, and