Immunomodulatory effect of vitamin K2: Implications for bone health.

OBJECTIVE

In women with postmenopausal osteoporosis, vitamin K2 appears to decrease the incidence of hip, vertebral, and non-vertebral fractures. Women with postmenopausal osteoporosis have more circulating activated T cells compared with healthy postmenopausal and premenopausal women, but the effects of vitamin K2 on T cells have 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.