Several epidemiologic studies have clearly demonstrated the correlation existing between vitamin D (VitD) deficiency and increased risk of developing cardiovascular disease, suggesting that it might have a hypothetical protective role in this clinical setting. To date, although many experimental studies have investigated the molecular mechanisms by which VitD might exert these effects, its role in protecting against athero-thrombosis is still partially unknown. This study has investigated whether VitD might exert anti athero-thombotic effects by preventing expression of adhesion molecules (CAMs) and Tissue Factor (TF), that are actively involved in atherothrombotic pathophysiology, in endothelial cells (HUVEC) stimulated with ox-LDL. Moreover, we have investigated whether VitD effects might be due to the NF-kB modulation.