Vitamin D refers to a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, iron, magnesium, phosphate, and zinc.
Very few foods contain vitamin D; synthesis of vitamin D (specifically cholecalciferol) in the skin is the major natural source of the vitamin. Dermal synthesis of vitamin D from cholesterol is dependent on sun exposure (specifically UVB radiation). [Source: Wikipedia, 2016]
Vitamin D is a steroid hormone responsible for enhancing intestinal absorption of calcium and the regulation of its homeostasis. The two common forms of Vitamin D are Vitamin D2 and Vitamin D3. Vitamin D3 is naturally produced in the human skin through the exposure to ultraviolet light and Vitamin D2 is mainly obtained from foods. Vitamin D is transported to the liver where it is metabolized to 25-hydroxy Vitamin D. In medicine, a 25-hydroxy Vitamin D blood test is used to determine Vitamin D concentration in the body. The blood concentration of 25-hydroxy Vitamin D is considered the best indicator of Vitamin D status.
Vitamin D deficiency is now recognized as a global epidemic. Virtually every cell in our body has receptors for Vitamin D, meaning that they all require “Sufficient” Level of Vitamin D for adequate functioning. The health risks associated with Vitamin D deficiency are far more severe than previously thought. Vitamin deficiency has been linked to various serious diseases: Osteoporosis, Osteomalacia, Multiple Sclerosis, Cardiovascular Diseases, Pregnancy Complications, Diabetes, Depression, Strokes, Autoimmune Diseases, Flu, Different Cancers, lnfectious Diseases, Alzheimer, Obesity and Higher Mortality etc.
Therefore, now detecting (25-0H) Vitamin D level is considered as “Medical/y Necessary Screening Test “, and maintaining sufficient levels not just to improve bone health, but to improve overall health and well-being.
Multiple guidelines for Vitamin D deficiency have been published by various health organizations; but a common recommendation remained to be established.