Objective—In women with postmenopausal osteoporosis, Vitamin K2 appears to decrease the incidence of hip, vertebral and non-vertebral fractures. Women with post-menopausal osteoporosis have more circulating activated T cells compared to healthy post-menopausal and pre-menopausal women, but the effects of Vitamin K2 on T-cells has not been studied. In this study, we have looked at T-cell suppression by Vitamin K2.
Materials and methods—Peripheral blood mononuclear cells (PBMCs) from three healthy donors were used. The PBMCs were stimulated with the mitogens phytohemagglutinin and concanavalin A, and T-cell proliferation was analyzed using flow cytometry based on carboxyfluorescein succinimidyl ester (CSFE) dye dilution.Results—Vitamin K2 (60 and 100 µM) inhibited T-cell proliferation. Vitamin K1 at the same concentrations did not inhibit T-cell proliferation.Conclusion—Vitamin K2 has immunomodulatory activities.