Augmentation of anticoagulant effect with vitamin D: possible therapeutic target for venous thromboembolism

Venous thromboembolism is a leading cause of morbidity and mortality especially in the elderly. Arrays of risk factors altering the blood flow, endothelial function and coagulability have been identified. However, the precise mechanisms that trigger clotting in major veins have not been fully elucidated. Activation of endothelial cells by hypoxia or inflammatory stimuli results in surface expression of adhesion molecules that facilitate the binding of circulating leukocytes and microvesicles. Subsequent leukocyte activation induces the release of potent procoagulant tissue factor that triggers thrombosis. Aging, immobility, smoking, surgery, OCP intake, cancer etc predispose to stasis, increased coagulation factor levels, impaired function of the venous valves, decreases in the efficacy of natural anticoagulants associated with the vessel wall, increased risk of immobilization and increased risk of severe infection. Prophylaxis is both mechanical and pharmacological with anticoagulation being the mainstay of treatment. Thus, better understanding the mechanisms of venous thrombosis may lead to the development of new therapeutic / preventive modalities. Recently, vitamin D, the sunshine hormone, has been in the limelight due to some experimental and epidemiological evidences showing its antithrombotic actions by various mechanisms. With emerging data about the potential association of vitamin D as an antithrombotic agent, our review has dissected the recent evidences of vitamin D having any beneficial effect on the markers of thrombosis or improvement among patients with deep vein thrombosis/pulmonary embolidm(DVT/PE). Keywords: Venous thromboembolism; Deep vein thrombosis; Vitamin D