25-Hydroxyvitamin D Deficiency Is Associated With Inflammation-Linked Vascular Endothelial Dysfunction in Middle-Aged and Older Adults

Abstract

We tested the hypothesis that vascular endothelial function, assessed by endothelium-dependent dilation, is related to serum vitamin D status among middle-aged and older adults without clinical disease, and that this is linked to inflammation. Brachial artery flow-mediated dilation, a measure of endothelium-dependent dilation, was lower ( P P =0.45). Among all subjects, brachial flow-mediated dilation was positively related to serum 25(OH)D (%Δ: r =0.35; P r =−0.06; P =0.61), the active form of vitamin D. Vascular endothelial cell expression of the proinflammatory transcription factor nuclear factor κB was greater in deficient versus sufficient subjects (0.59±0.07 versus 0.44±0.05; P P P r =−0.62; P P <0.05). Inadequate serum 25(OH)D is associated with vascular endothelial dysfunction among healthy middle-aged/older adults, and this is mediated in part by nuclear factor κB–related inflammation. Reduced vitamin D receptor and 1-α hydroxylase may be molecular mechanisms linking vitamin D insufficiency to endothelial dysfunction.