الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Breast cancer is the most common malignancy among women worldwide. The origin of breast cancer is multifactorial; however, some factors may increase the risk of breast cancer including the age, family history, diet, presence of benign mammary disease, environment, and genetic factors related to serum vitamin D level and vitamin D pathway gene polymorphisms.
Vitamin D is a fat-soluble vitamin. Dermal synthesis is the primary source of vitamin D for most individuals. Diet and supplements are generally minor contributors. It undergoes the first hydroxylation in the liver to form 25-hydroxyvitamin D (25(OH)D). A second hydroxylation takes place in the kidneys and other tissues to form an active form of vitamin D (1,25-dihydroxyvitamin D) (1,25(OH)2D).
Vitamin D has both rapid non-genomic actions that include; calcium absorption in the small intestine, bone mineralization acting with parathyroid hormone and maintenance of calcium homeostasis in the blood, and slow genomic actions through binding to its receptor called vitamin D receptor (VDR).
Vitamin D deficiency has become a major concern after the discovery of great extent of populations suffering with its varied health consequences. Reports showed that most world’s population are not getting sufficient amount of Vitamin D due to the current lifestyle and environmental factors that limit sunlight exposure. Breast cancer research in the Middle East is extremely limited and genetics studies about cancer within Egypt are scarce except for few studies that screen gene polymorphism.
Studies have demonstrated a relationship between low vitamin D levels and breast cancer; probably due to its anti-proliferative, anti-inflammatory effects, immune-modulating properties and its role in DNA repair.