25-hydroxy Vitamin D3 is an intermediate in the biosynthesis of 1α,25-dihydroxy vitamin D3 (calcitriol; Item No. 71820), a vitamin D receptor (VDR) agonist that has multiple functions, including stimulation of calcium absorption, insulin secretion, and cell proliferation and differentiation.1,2,3 It is produced from vitamin D3 (Item No. 11792) by 25-hydroxylase/CYP2R1 and bound to vitamin D binding protein (DBP) and albumin in the liver, then secreted into the bloodstream where it is the major circulating form of vitamin D.1 25-hydroxy Vitamin D3 is transported to the kidney where it is hydroxylated by 1α-hydroxylase/CYP27B1 or 24-hydroxylase/CYP24A1 to produce 1α,25-dihydroxy vitamin D3 or 24,25-dihydroxy vitamin D3, respectively. Conversion of 25-hydroxy vitamin D3 to 1α,25-dihydroxy vitamin D3 is stimulated by parathyroid hormone (PTH) and inhibited by calcium, phosphorus, or FGF23. Serum 25-hydroxy vitamin D3 levels have been widely used as a marker of vitamin D status.2 Increased serum 25-hydroxy vitamin D3 levels are associated with increased bone density in patients with osteoarthritis, as well as reduced risk of colorectal, breast, and prostate cancer, whereas decreased serum 25-hydroxy vitamin D3 levels have been found in children with nutritional rickets, a condition caused by vitamin D deficiency and characterized by reduced bone density.2,4,5 Cayman's 25-hydroxy Vitamin D3 Rabbit Monoclonal Antibody (Clone RM3) can be used for ELISA.WARNING This product is not for human or veterinary use.
