Severe vitamin D deficiency is associated with endothelial inflammation in healthy individuals even in the absence of subclinical atherosclerosis.

Vitamin D has beneficial effects, some of which involve the cardiovascular system. No study to date has investigated the association between serum endocan levels, as a biomarker of endothelial inflammation, and vitamin D levels in the absence of subclinical atherosclerosis detected by carotid intima-media thickness (CIMT) in healthy individuals. Subjects were categorized into three groups based on vitamin D levels according to Endocrine Society guidelines. Mean CIMT was calculated from six measurements on two scans. Statistical significance was set at p < 0.05, and all testing was two-sided. The concentration of serum endocan was 802.8 ± 411.4 ng/L in the group with the lowest serum vitamin D level, 454.8 ± 334.3 ng/L in the mild/moderately low serum vitamin D level group, and 269.4 ± 180.2 ng/L in the group with normal serum vitamin D levels (p < 0.01). Receiver operating characteristics curve analysis revealed that a serum vitamin D concentration of 7.5 ng/mL had a 97% sensitivity and 81% specificity for the prediction of serum endocan level greater than 270 ng/L, which could be an indicator for endothelial inflammation. Demonstrating that vitamin D deficiency can cause endothelial damage in the early period of atherosclerosis without the development of clinical cardiovascular disease will have a pivotal role in the prevention of cardiovascular mortality and morbidity.