الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Vitamin D is a fat soluble vitamin generated in human skin by ultraviolet (UV) light. It has a key role in calcium homeostasis and promotion of favourable health outcomes.
Vitamin D deficiency is now recognized as a pandemic. Vitamin D deficiency and insufficiency is a global health issue that afflicts more than one billion children and adults worldwide. It has been estimated that approximately 30% and 60% of children and adults worldwide are vitamin D deficient and insufficient respectively.
The consequences of vitamin D deficiency cannot be under estimated. There has been an association of vitamin D deficiency with a myriad of acute and chronic illnesses including preeclampsia, childhood dental caries, periodontitis, autoimmune disorders, infectious diseases, cardiovascular disease, deadly cancers, type 2 diabetes and neurological disorders.
Sun exposure is the major source of vitamin D so inadequate sun exposure is the main cause of vitamin D deficiency .Very few foods naturally contain vitamin D, and foods that are fortified with vitamin D are often inadequate to satisfy either a child’s or an adult’s vitamin D requirement.
Vitamin D status is frequently assessed by measuring serum concentration of 25–hydroxyvitamin D [25-(OH)D], which reflects total vitamin D from both dietary intake and sunlight exposure. Endocrine Society’s Practice Guidelines recommend screening for vitamin D deficiency in individuals at risk for deficiency and not recommend population screening for vitamin D deficiency in individuals who are not at risk some groups in the community are at increased risk of vitamin D deficiency. They include naturally dark-skinned people, those who cover their skin for religious or cultural reasons, the elderly, infants of vitamin D deficient mothers, obese individuals, people with fat malabsorption, Patients with chronic granuloma-forming disorders (sarcoidosis, tuberculosis, and chronic fungal infections), patients with nephritic syndrome lose 25(OH)D bound to the vitamin D-binding protein in the urine and Patients on a wide variety of medications, including anticonvulsants and medications to treat AIDS/HIV are at risk.
In the published Endocrine Society’s Practice Guidelines on Vitamin D, vitamin D deficiency was defined as a 25(OH)D < 20 ng/mL, insufficiency as 21–29 ng/mL and sufficiency as at least 30 ng/mL for maximum musculoskeletal health.
In this cross sectional study, the serum circulating 25-hydroxyvitamin D was estimated in 6o Egyptian female subjects aged between 18 and 80 years. The subjects were classified into three groups : group (I) included 20 non veiled females ,group (II) included 20 partially veiled females (with Hijab) and group (III) included 20 completely veiled females (with Niqab). All the participants were subjected to the following: full history, taking, vitamin D questionnaire including the following items (age, colour of skin, past medical history, medications, residence information (urban or rural), diet, time of sun exposure and physical activity.), complete physical examination, laboratory assessment including: complete blood count, liver enzymes (ALT, AST),serum albumin, renal functions tests (serum creatinine, serum urea),serum calcium (total and ionized),serum 25-hydroxyvitamin D by enzyme immunoassay for the quantitative measurement of 25-hydroxyvitamin D2 and D3(25-OHD2 and 25-OHD3) in serum (ELISA) and Dual emission X-ray absorptionmetry scan (DEXA scan).
The results of present study showed that there was no significant difference between the three groups according to age, body mass index, the menstrual cycle (premenopausal and postmenopausal).
There was a statistically significant difference between the three groups according to the time of sun exposure per day (p= 0.039).The longest time of sun exposure was in group I (Non – Veiled).
There was a statistically significant difference between the three groups according to serum total calcium (p=0.020).The highest serum total calcium was in group I(Non – Veiled).
25-)OH ( D ranged from 20.0 to 40.0 ng/ml with a mean value of 28.0 ± 5.62 in group I (Non – Veiled) ,it ranged from 13.80 to 54.0 ng/ml with a mean value of 24.02 ± 9.64 in group II (Hijab ) and ranged from 7.0 to 20.70 ng/ml with a mean value of 13.30 ± 4.48 in group III (Niqab).
There was a statistically significant difference between the three groups according to 25 (OH) D level (p= <0.001). 25 (OH) D level was the highest in group I and the least in group III.
25 (OH) D serum level was significantly negatively correlated to BMI ,and significantly positively correlated to time of sun exposure and serum total calcium ,while there was no statistically significant correlation between age and 25 )OH( D serum level.
Although there was a statistically significant difference between the three groups according to vitamin D level (p= <0.001), there was no significant difference between the three groups according to dexa scan findings (p=0.091) and there was no association between vitamin D deficiency and osteoporosis.