Effect of Dietary Vitamin K2Supplementation on Bone Mineral Density in Ovariectomized Rats

Abstract

Vitamin K has been suggested to plays a role in bone metabolism. The objective of this study was to determine whether vitamin K₂ supplementation is related to bone mineral density, bone formation markers, and bone resorption in ovari-ectomized(OVX) rats. Forty Sprague-Dawley female rats (body weight, 200 ± 10g) were divided into lour groups: a sham group fed a control diet, a sham group fed a vitamin K₂ supplemented diet, OVX fed a control diet, and OVX fed a vitamin K₂ supplemented diet (3.5 mg vitamin K₂/kg diet). All rats were fed the experimental diets for 6 weeks, and deionized water was provided ad libitum. Serum alkaline phosphatase activity (ALP), osteocalcin, and urinary deoxy-pyridinoline crosslink values were measured as markers of bone formation and resorption. Bone mineral density(BMD) and bone mineral content were measured in the spine and femur using PIXlmus (GE Lunar Co., Madison, WI, USA). No significant differences in body weight gain, food intake, or food efficiency ratio were observed between the control and experimental groups. Serum ALP, osteocalcin, and urinary crosslink values were not significantly different between the vitamin K₂ supplemented groups. No significant differences were observed for any of the variables in the sham group. Spine BMD values were significantly lower in the OVX than those in the sham groups. Spine and femur BMD per weight of vitamin K1 tended to be higher than the control diet group within the OVX group, but no significant differences were observed. In conclusion, dietary vitamin K₂ supplementation may have a beneficial effect on spine and femur BMD in OVX rats. Further research is needed to understand the potential benefits of vitamin K₂ on bone loss in OVX rats.