A comparative study between Vitamin K1 and K2 on vascular calcification in hemodialysis patients: a randomized controlled trial

Background: Vascular calcification is a common complication of
end stage renal disease patients, an important cause of cardiovascular
disease and all-cause mortality. Vitamin K is essential for the activation
of matrix Gla protein (MGP), a powerful inhibitor of tissue calcification.
Different forms of vitamin K have been proposed to have a good impact on
vascular calcification. However, clinical data are still limited on
efficacy and safety of different forms of vitamin K. Methods : A
prospective, randomized, placebo-controlled study that included 120
eligible hemodialysis patients who were randomly assigned to either
vitamin k1 group (10 mg phytomenadione thrice weekly) or vitamin k2 group
(90 ug daily) or placebo group for 3 months. Serum MGP, calcium,
phosphorus, their product, and intact parathyroid hormone (iPTH) levels,
were all assessed at baseline and at the end of the study. Results: There
were significant increase in percentages of change in MGP levels in
Vitamin k2 group (700%) compared to (78%) in Vitamin k1 & (40%) in
placebo groups. No correlations observed between calcium,
phosphorous and PTH and MGP levels at baseline or after
treatment. None of the treatment group patients experienced any
adverse effects. Conclusion: Vitamin k supplementation was
tolerable and effective with k2 form showing superiority over k1 in their
impact on MGP levels among hemodialysis patients. ClinicalTrials.gov
registration number: NCT04477811.

背景：血管钙化是终末期肾病患者的常见并发症，亦是心血管疾病与全因死亡的重要致病因素。维生素K是基质Gla蛋白（matrix Gla protein, MGP）激活的必需物质，而MGP是强效的组织钙化抑制剂。已有研究提出不同形式的维生素K可对血管钙化产生积极影响，但目前关于不同形式维生素K的疗效与安全性的临床数据仍较为有限。
方法：本研究为一项前瞻性、随机、安慰剂对照试验，共纳入120名符合入组标准的血液透析患者，按随机分配原则分为三组：维生素K1组（每周3次，每次10mg植物甲萘醌）、维生素K2组（每日90μg）及安慰剂组，干预周期为3个月。分别于基线及研究终点时检测受试者的血清MGP、钙、磷、钙磷乘积以及全段甲状旁腺激素（intact parathyroid hormone, iPTH）水平。
结果：与维生素K1组的78%及安慰剂组的40%相比，维生素K2组的MGP水平变化百分比显著升高（700%）。在基线及治疗后，钙、磷与甲状旁腺激素水平和MGP水平均未观察到相关性。所有治疗组受试者均未出现任何不良反应。
结论：补充维生素K具有良好的耐受性与有效性，其中维生素K2形式在改善血液透析患者血清MGP水平方面的效果优于维生素K1。本研究在ClinicalTrials.gov的注册编号为NCT04477811。