25-hydroxyvitamin D, biomarkers of endothelial dysfunction and subclinical organ damage in adults with hypertension.

Background: The mechanism that underlies the association between low 25-hydroxyvitamin D [25(OH)D] and hypertension is not well understood; it seems to involve regulation of the renin-angiotensin-aldosterone system and the impact on endothelial function, cardiac remodeling, and subclinical organ damage. Vitamin D supplementation presents an ambiguous effect on endothelial function and arterial stiffness. We assess serum 25(OH)D3, biomarkers of endothelial dysfunction (soluble intercellular adhesion molecule [sICAM], C-reactive protein [CRP], homocysteine [Hcy]) and subclinical organ damage in adults with newly diagnosed untreated hypertension.