In Healthy Adults, Biological Activity of Vitamin D, as Assessed by Serum PTH, Is Largely Independent of DBP Concentrations

摘要: Vitamin D insufficiency, as measured by 25-hydroxyvitamin (25[OH]D) levels, has been associated with important health outcomes. The majority of vitamin in circulation is bound to D–binding protein (DBP) and albumin, recent genetic studies have demonstrated that serum DBP a major determinant 25(OH)D concentrations adults. impact circulating levels on D's biologic action, unclear, but particular relevance epidemiology, because lack control for could strongly influence the association disease. Serum parathyroid hormone (PTH) can act biological readout activity. We therefore assessed relationship between total free PTH without adjusting DBP, 2073 subjects European descent. Total correlated positively (r = 0.19, p = 1.8 × 10−17) whereas negatively (r = −0.14, p = 5.0 × 10−12). (r = −0.29, p = 1.3 × 10−39; r = −0.26, p = 1.9 × 10−33, respectively). Including age, body mass index (BMI), sex, estimated glomerular filtration rate, calcium, season blood draw covariates, were significantly log-transformed (lnPTH) (linear term: β = −0.010, p < 0.0001, squared β = 0.00004, p < 0.0001) this was not changed DBP. These findings provide evidence largely D–sufficient cohort, effect mainly independent concentration. Accordingly, study may useful information investigating D, © 2014 American Society Bone Mineral Research.