Volpe Stella L, Leung May May, Giordano Heather
Division of Biobehavioral and Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104-6096, USA.
Nutr Res. 2008 Sep;28(9):577-82. doi: 10.1016/j.nutres.2008.06.006.
Because of its role in osteoblastic metabolism, vitamin K has been studied with respect to bone. However, there has been limited research examining the influence of long-term vitamin K supplementation on bone mineral density (BMD). Therefore, the purpose of this study was to assess the impact of 6 months of vitamin K supplementation on BMD and biomarkers of bone in pre- and perimenopausal women. Based on previous work, we hypothesized that vitamin K would improve BMD and biochemical markers of bone formation. A double-blind, placebo-controlled, randomized trial is an effective way to study the impact of long-term supplementation. Thus, 14 pre- and perimenopausal women, 25 to 50 years of age, were randomly assigned to an experimental group (E) that received 600 microg/d of vitamin K in the form of phylloquinone (K(1)) or a control group (C) that received identical-looking placebo tablets. Regional BMD and percent body fat, measured by dual-energy x-ray absorptiometry, and serum osteocalcin and urinary N-telopeptide levels were all assessed at 0, 3, and 6 months. When BMD was measured across time, C had a significant increase (P = .011) in greater trochanter BMD compared to E. The E group had a nonsignificant increase (P = .067) in shaft BMD compared to the C group. There was no significant difference between E and C in serum osteocalcin concentrations over time. Urinary N-telopeptide levels increased significantly over time in E compared to C (P = .008). Six months of 600 microg/d vitamin K(1) supplementation did not improve regional BMD in this group of pre- and perimenopausal women.
由于维生素K在成骨细胞代谢中的作用，人们对其与骨骼的关系进行了研究。然而，关于长期补充维生素K对骨密度（BMD）影响的研究有限。因此，本研究的目的是评估补充维生素K 6个月对绝经前和围绝经期女性骨密度及骨生物标志物的影响。基于之前的研究，我们假设维生素K会改善骨密度和骨形成的生化指标。双盲、安慰剂对照、随机试验是研究长期补充影响的有效方法。因此，14名年龄在25至50岁的绝经前和围绝经期女性被随机分配到实验组（E组），该组每天接受600微克以叶绿醌（K₁）形式存在的维生素K，或对照组（C组），该组接受外观相同的安慰剂片。在0、3和6个月时评估了通过双能X线吸收法测量的局部骨密度、体脂百分比以及血清骨钙素和尿N-端肽水平。随着时间推移测量骨密度时，与E组相比，C组大转子骨密度有显著增加（P = 0.011）。与C组相比，E组骨干骨密度有不显著的增加（P = 0.067）。随着时间推移，E组和C组血清骨钙素浓度没有显著差异。与C组相比，E组尿N-端肽水平随时间显著增加（P = 0.008）。在这组绝经前和围绝经期女性中，每天补充600微克K₁维生素K 6个月并未改善局部骨密度。
