Is vitamin D supplementation a new hope for the therapy of the septic shock?

Vitamin D is mainly known for its traditional role in the bone mineralization and calcium homeostasis. Recent studies have shown that vitamin D receptors (VDR) are present in almost all the tissues and cells in the human body. In addition, several studies have revealed that vitamin D is important in immunomodulation, regulation of inflammation and cytokines, cell proliferation, cell differentiation, apoptosis, angiogenesis, muscle strength, and muscle contraction. Patients with sepsis have high mortality rate and high deficiency in vitamin D. In addition, septic patients have decreased vitamin D binding-protein (DBP) levels which further exacerbate the vitamin D deficiency. The role of vitamin D treatment in sepsis syndrome has been evaluated in animal model of sepsis where 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] administration was associated with improved blood coagulation parameters in sepsis associated with a disseminated intravascular coagulation. Vitamin D treatment in vitro has also been demonstrated to modulate levels of the systemic inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6), as well as inhibit the lipopolysaccharide (LPS)-induced activation and vasodilation of vascular endothelium. Vitamin D may enhance the induction of the antimicrobial peptides, cathelicidin and b-defensin, which have been described on mucosal and epithelial surfaces acting as the body's first line of defense against viral and bacterial pathogens. Vitamin D supplementation may divert attention from relatively simple, natural, and low-costmethods of preventing severe sepsis and septic shock. Further prospective, randomized and controlled clinical trials of adjunctive vitamin D therapy in patients who are vitamin D deficient are needed in the management of human sepsis syndrome.