Читать книгу Vitamin D in Clinical Medicine - Группа авторов - Страница 41

Vitamin D-binding protein (DBP) is known as the main transporter of vitamin D metabolites in the blood. DBP actions, however, go beyond vitamin D physiology. Peculiar characteristics and several functions of DBP make it an interesting molecule. The circulating concentration (5 × 10^–6M) is remarkably higher than the main ligand, 25-hydroxyvitamin D (25[OH]D; 5 × 10^–8M), suggesting that it might have other functions [1]. Besides acting as a vitamin D carrier, DPB has a major role in the clearance of G-actin monomers from plasma [2] and seems to directly regulate neutrophil, macrophage, and osteoclast activity [3, 4]. DBP deletion in humans has so far not been reported, suggesting that its absence may be lethal [1]. It is a highly polymorphic protein and multiple assays have been used to evaluate the concentration of DBP. The findings of discrepant results have given rise to many debates [5].

Recently, DBP has returned to the spotlight due to the discussion about its role in vitamin D physiology, which will be discussed in this chapter.