Coronary artery disease (CAD) remains a major public health burden. Emerging research has suggested an association between vitamin D insufficiency and CAD. Vitamin D binding protein (VDBP) is the primary vitamin D carrier and many of its genetic polymorphisms are able to induce the expression of proteins with different affinities for the vitamin, which in turn, might affect its serum levels and CAD incidence. The book portrays a two-year research project that aimed at exploring the effect of genetic variation in GC gene (the gene encoding VDBP) on the serum vitamin D levels, parathyroid hormone levels and the incidence of CAD in Egyptian population. The extensive spread of CAD among Egyptians ranks this work of supreme importance. The book is mainly written to draw attention of readers in the areas of genomics, pharmacology, physiology, cardiology, clinical biochemistry and molecular biology.