维生素K如何促进血糖的健康代谢？

        最近的一项研究发现，维生素K可以将患II型糖尿病的风险降低51%，并抑制代谢综合征。

                ——By Suzanne Schiff  

      二型糖尿病没有治愈方法。但2100万成年人也有了新的希望。最近的研究表明，维生素K在葡萄糖代谢中起着重要作用。这可以帮助糖尿病患者避免高血糖损害眼睛、肾脏、神经和心脏。维生素K也可能有助于预防II型糖尿病的发病。

维生素K与Ⅱ型糖尿病风险

         维生素K以帮助血液正常凝固、保持骨密度和防止血管钙化而闻名，但它的好处远远不止于此。几项大规模研究分析了维生素K与II型糖尿病的关系，共检查了4万多人。有研究表明，维生素K-如K1（菲洛奎酮）或K2（门那醌）的摄入增加与降低患II型糖尿病的风险有关。在一项针对老年人的研究中，与那些减少或未能改变维生素K摄入量的人相比，增加饮食维生素K摄入量的受试者患糖尿病的风险降低了51%。这项研究进一步证明，每天额外摄入100 mcg维生素K1，二型糖尿病的风险降低了17%。而2018年的一项研究显示，II型糖尿病患者的血液维生素K水平比同龄非糖尿病患者低2.7倍以上。低水平的维生素K与胰岛素抵抗有关，胰岛素抵抗是II型糖尿病血糖代谢的核心陷。

维生素K改善葡萄糖代谢 

         最近的研究表明，补充维生素K（K1或K2）可以直接降低II型糖尿病的风险。在一项对355名60-80岁的成年人进行的研究中，500 mcg/天的K1持续3年，男性胰岛素抵抗和血胰岛素水平显著降低； 一项对82名患有糖尿病前期（通常表明胰岛素敏感性差，可发展为II型糖尿病）的妇女（平均年龄：40岁）的研究表明，1000微克/天的K1可在短短四周内显著增加胰岛素敏感性并降低胰岛素水平；在一项对33名健康青年（中位年龄29岁）进行的为期四周的研究中，补充维生素K2导致胰岛素敏感性增加。研究表明，这两种维生素K1和K2对葡萄糖代谢、胰岛素抵抗和其他代谢功能都有积极影响。这些结果对糖尿病患者和有发展糖尿病风险的人有很大的希望。     

改善机制             

          2018年发表的一项研究进一步揭示了维生素K如何改善葡萄糖代谢。荷兰研究人员给214名绝经后妇女服用180 mcg/天的维生素K2或安慰剂，为期三年。 正如预期的那样，他们发现维生素K激活了一组称为Gla蛋白的蛋白质，8种因其在骨和矿物质代谢中的作用而闻名。然而，Gla蛋白遍布全身，在调节新陈代谢方面起着重要作用。  在接受维生素K的组中，与其他参与者相比，Gla蛋白活性增加最多的一个子组腹部脂肪质量显著减少。该组的体重指数、腰围和臀围以及腰臀比也显著降低。所有这些结果都会降低患代谢综合征和II型糖尿病的风险。维生素K还可以提高脂联素的水平，脂联素是一种有益的激素，有助于调节糖的代谢。最后，一系列的临床前研究表明，维生素K降低了核因子kappa B（NF-kB）的活性，NF-kB是体内炎症的主要驱动因素。

总结             

          II型糖尿病是不可治愈的，但如果生活方式和营养选择结合得当，它是可以预防的。越来越多的证据表明，那些摄入和血液中维生素K水平较高的人（以K1和K2的形式）已经大大降低了患Ⅱ型糖尿病的风险。研究表明，服用维生素K的人有助于改善葡萄糖代谢，改善胰岛素敏感性，降低体脂，所有这些都可以预防II型糖尿病和代谢综合征。增加维生素K还可以通过控制损害性高血糖而使那些已经患有糖尿病的人受益。

英文原文：

There’s no cure for type II diabetes. But there is new hope for the 21 million adults living with it.1

Recent research has shown that vitamin K plays an important role in glucose metabolism. That can help diabetics avoid the high blood sugar that damages the eyes, kidneys, nerves, and heart.

Vitamin K may also help prevent the onset of type II diabetes.2

Vitamin K and Risk of Type II Diabetes

Vitamin K is best known for helping blood properly clot, maintaining bone density, and preventing vascular calcifications.2,4-7

But its benefits go far beyond that.2,8,9
Several large-scale studies have analyzed the association between vitamin K and type II diabetes, examining more than 40,000 people in total.2,3,10,11

Together, these studies show that increased intake of vitamin K—as either K1 (phylloquinone) or K2 (menaquinone)—is linked to a reduced risk of developing type II diabetes.2,3,10

In one study of older adults, subjects who increased their dietary vitamin K intake had a 51% reduction in their risk for developing diabetes, compared with those who decreased or failed to change their vitamin K intake.3

The study further demonstrated a 17% reduction in the risk for type II diabetes for each additional intake of 100 mcg/day of vitamin K1.3

And a 2018 study revealed that people with type II diabetes had blood vitamin K levels more than 2.7 times lower than non-diabetic patients of the same age.11

Lower levels of vitamin K are linked to greater insulin resistance, the core metabolic defect in type II diabetes.11

Vitamin K Improves Glucose Metabolism
Recent studies show that supplementing with vitamin K (either as K1 or K2) can directly reduce the risk of type II diabetes. Among the results:

In a study of 355 adults 60-80 years old, 500 mcg/day of K1 for three years led to significant reductions in insulin resistance and blood insulin levels in men.12
A study of 82 women (mean age: 40 years) with prediabetes (a condition often indicative of poor insulin sensitivity, that can progress to type II diabetes) showed that 1,000 mcg/day of K1 resulted in significant increases in insulin sensitivity and reductions in insulin levels in just four weeks.13

In a four-week study of 33 healthy young men (median age 29), supplementation with vitamin K2 led to increased insulin sensitivity.14

Research shows that both forms of the vitamin, K1 and K2, have a positive impact on glucose metabolism, insulin resistance, and other metabolic functions. These results hold out great promise for people with diabetes and those at risk of developing it.

How It Works

A study published in 2018 sheds further light on how vitamin K improves glucose metabolism.8

Dutch researchers gave 214 post-menopausal women either 180 mcg/day of vitamin K2 or a placebo over a period of three years.8

As expected, they found that vitamin K activated a group of proteins called Gla proteins,8 known for their role in bone and mineral metabolism. However, Gla proteins are found throughout the body, and are instrumental in regulating metabolism.

In the group that received vitamin K, a subset who showed the largest increase in Gla protein activity experienced significant reduction in abdominal fat mass, compared with other participants.8

That group also had a significant reduction in body mass index, waist and hip circumference, and waist-hip ratio. All these results translate to a reduced risk for developing metabolic syndrome and type II diabetes.8

Vitamin K has also been shown to boost levels of adiponectin, a beneficial hormone that helps regulate the metabolism of sugars.2

Finally, a series of preclinical studies have indicated that vitamin K reduces activity of nuclear factor kappa B (NF-kB), the primary driver of inflammation in the body.15

Summary

Type II diabetes isn’t curable, but it is preventable, given the right combination of lifestyle and nutritional choices.

There’s growing evidence that those with higher intake and blood levels of vitamin K (in the form of both K1 and K2) have substantially reduced risks of developing type II diabetes.

Studies show that people taking vitamin K have improved glucose metabolism, improved insulin sensitivity, and lower body fat, all of which protect against type II diabetes and metabolic syndrome.

Increasing vitamin K can also benefit those who already have diabetes, by keeping damaging high blood sugar under control.

参考文献：

Bullard KM, Cowie CC, Lessem SE, et al. Prevalence of Diagnosed Diabetes in Adults by Diabetes Type - United States, 2016. MMWR Morb Mortal Wkly Rep. 2018 Mar 30;67(12):359-61.

Bourron O, Phan F. Vitamin K: a nutrient which plays a little-known role in glucose metabolism. Curr Opin Clin Nutr Metab Care. 2019 Mar;22(2):174-81.

Ibarrola-Jurado N, Salas-Salvado J, Martinez-Gonzalez MA, et al. Dietary phylloquinone intake and risk of type 2 diabetes in elderly subjects at high risk of cardiovascular disease. Am J Clin Nutr. 2012 Nov;96(5):1113-8.

Gast GC, de Roos NM, Sluijs I, et al. A high menaquinone intake reduces the incidence of coronary heart disease. Nutr Metab Cardiovasc Dis. 2009 Sep;19(7):504-10.

Available at: http://www./Magazine/2015/CE/CE_Turning-To-Stone/Page-01. Accessed November 10, 2016.

Villa JKD, Diaz MAN, Pizziolo VR, et al. Effect of vitamin K in bone metabolism and vascular calcification: A review of mechanisms of action and evidences. Crit Rev Food Sci Nutr. 2017 Dec 12;57(18):3959-70.

Komai M, Shirakawa H. [Vitamin K metabolism. Menaquinone-4 (MK-4) formation from ingested VK analogues and its potent relation to bone function]. Clin Calcium. 2007 Nov;17(11):1663-72.

Knapen MHJ, Jardon KM, Vermeer C. Vitamin K-induced effects on body fat and weight: results from a 3-year vitamin K2 intervention study. Eur J Clin Nutr. 2018 Jan;72(1):136-41.

Dam V, Dalmeijer GW, Vermeer C, et al. Association Between Vitamin K and the Metabolic Syndrome: A 10-Year Follow-Up Study in Adults. J Clin Endocrinol Metab. 2015 Jun;100(6):2472-9.

Beulens JW, van der AD, Grobbee DE, et al. Dietary phylloquinone and menaquinones intakes and risk of type 2 diabetes. Diabetes Care. 2010 Aug;33(8):1699-705.

Dihingia A, Ozah D, Ghosh S, et al. Vitamin K1 inversely correlates with glycemia and insulin resistance in patients with type 2 diabetes (T2D) and positively regulates SIRT1/AMPK pathway of glucose metabolism in liver of T2D mice and hepatocytes cultured in high glucose. J Nutr Biochem. 2018 Feb;52:103-14.

Yoshida M, Jacques PF, Meigs JB, et al. Effect of vitamin K supplementation on insulin resistance in older men and women. Diabetes Care. 2008 Nov;31(11):2092-6.

Rasekhi H, Karandish M, Jalali MT, et al. Phylloquinone supplementation improves glycemic status independent of the effects of adiponectin levels in premonopause women with prediabetes: a double-blind randomized controlled clinical trial. J Diabetes Metab Disord. 2015;14(1):1.

Choi HJ, Yu J, Choi H, et al. Vitamin K2 supplementation improves insulin sensitivity via osteocalcin metabolism: a placebo-controlled trial. Diabetes Care. 2011 Sep;34(9):e147.

Dihingia A, Ozah D, Baruah PK, et al. Prophylactic role of vitamin K supplementation on vascular inflammation in type 2 diabetes by regulating the NF-kappaB/Nrf2 pathway via activating Gla proteins. Food Funct. 2018 Jan 24;9(1):450-62.