The Vitamin D Test is a serum analysis that quantitates 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 metabolites. The metabolite 25-hydroxyvitamin D is the major circulating form of vitamin D in the body and the best indicator of a patient’s true vitamin status. The major biologic function of vitamin D is to maintain the normal blood levels of calcium and phosphorus involved in bone mineralization. Vitamin D also influences expression of more than 2,000 genes, including those responsible for regulation of cellular proliferation, cell differentiation, apoptosis, and angiogenesis. The immune-modulating effects of vitamin D are profound, as evidenced by the many conditions that are associated with vitamin D deficiency. The Vitamin D Test can help to determine if sun exposure is adequate, if dietary vitamin D is sufficient, and to assess the likelihood of malabsorption or liver disease.

I am agree with you this test is very necessary for our body..