Vitamin D And Vitamin D Related Disease

Vitamin D is the essential nutrients for body and obtained through the sunlight,oral intake and fetal maternal transfer.Vitamin D generate 25?OH?D as a result of 25 hydroxylase which in mitochondria and microsome of liver,the latter convert into 1,25?OH?₂D in prostate,breast,colon,and immune cells,combining with specific intracellular vitamin D receptor,regulating immune and cell growth,developing autocrine and paracrine effects.25?OH?D also can generate 25?OH?₂D by 1-? hydroxylase in renal tubular epithelial cell mitochondria,playing a role in endocrine function,such as,regulating calcium and phosphorus metabolism and insulin release.25?OH?D has high concentration,long half-life period,stable nature in the blood,so it is a reliability index to reflect vitamin D nutritional status in the body.Vitamin D's nutritional status judgment standard has not yet reached a consensus,the current standard that more recognized is:1)vitamin D deficiency rickets: <27.5nmol/L?some countries use 25.0nmol/L?;2)vitamin D deficiency: 27.5 to 50.0nmol/L;3)vitamin D insufficient:50.0⁷5.0nmol/L;4)vitamin D adequacy:75.0to250.0nmol/L;5)vitamin D overdose: 250.0³75.0nmol/L;6)vitamin D intoxication: >375.0nmol/L.The latest research can evaluate human vitamin D nutritional status that suit for human by the levels relationship between serum 25?OH?D and parathyroid hormone.According to current research,vitamin D deficiency is very common.National Institutes of Health,the European and North American society of Endocrine,International Osteoporosis Group,Chinese Nutrition Society have issued various of guidelines or recommendations,which improved the recommendation intake and tolerated highest intake in the body,and encouraged vitamin D supplementation.Suitable amount of vitamin D is essential for health and vitamin D lack is closely related in many diseases occurrence and development,including bone disease,respiratory system disease,endocrine disease,digestive system diseases,cardiovascular disease,kidney disease,nervous system disease tumor and so on.For the skeletal system disease,vitamin D act on the gut to increase intestinal calcium and phosphorus absorption,on kidney to increase the calcium and phosphorus re-absorption,on bone to promote bone resorption and calcium salts deposition,thereby regulating calcium and phosphorus metabolism and bone mineralization.These effects are achieved through the vitamin D receptor.For non skeleton system diseases,Vitamin D can act on epithelial cells,monocytesmacrophages or dendritic cells by Toll receptor,improve the innate immunity level,promote antimicrobial peptides?including antibiotics and LL37?release and increase clearance of pathogens.At the same time,vitamin D can also regulate the acquired immune,including immune cells?Th1,Th2 and regulatory T cells and B cells?and cytokines,such as up-regulation the Th2,regulatory T cells,IL-4,IL-5,IL-10 and TGF-? levels,inhibiting Th1,IL-1,IL-2,IL-6,IL-8,IL-12,IL-17,IFN??TNF?,and so on.In summary,the reason that vitamin D has an impact in disease occurrence and development is mainly regulating the immune function,reducing inflammation,inhibiting the immune response.In addition,factors that associated with disease occurrence also includes vitamin D receptor gene,hydroxylase gene and polymorphism of vitamin D binding protein gene.The treatment effect of skeletal diseases though vitamin D has been widely recognized,but the treatment and long-term effect of non skeletal diseases is not clear,and more research that supplying vitamin D's role in the prevention and treatment non skeletal diseases should be done.