الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Asthma is a heterogeneous disease, usually characterized by chronic
airway inflammation. It is defined by the history of respiratory symptoms
such as wheeze, shortness of breath, chest tightness and cough that vary
over time and in intensity, together with variable expiratory airflow
limitation Asthma prevalence among children and teenagers is 8.4% in
Egypt,The prevalence of BA among school children ranged from 6.2% in
Assiut city in Upper Egypt up to 46.1% in Cairo It was found that the
prevalence of asthma among school children in Delta region was 7.7%Vitamin D is a fat-soluble sec0ster0id (aprohormone) known as
calciferol. Vitamin (D) receptors present all over the human body, from
bones and muscles to the central nervous system The major natural source of the vitamin is synthesis of
cholecalciferol in the skin from cholesterol through a chemical reaction
that is dependent on sun exposure.