Vitamin K Improves Glucose Metabolism and Insulin Sensitivity
By Mae Chan
Average intakes of vitamin K in the United States, United Kingdom, Australia and Canada are far less than recommended intakes. A review of scientific literature is highlighting the benefits of vitamin K to help reduce the risk of diabetes by improving insulin sensitivity and glucose metabolism.
What is Vitamin K?
If you’ve read about vitamins A, B, C, D, and E, you might feel like we’ve missed a few vitamins as we jump over to vitamin K. It’s important to know that vitamin K makes a variety of unique contributions to our health, and our knowledge about these contributions has been expanding in new and unexpected ways.
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There are three basic types of vitamin K. Their common names are K1, K2, and K3. K1 is required for green plants to conduct the process of photosynthesis. Phylloquinone, also known as phytonadione, (vitamin K1) is found in green leafy vegetables such as lettuce, broccoli and spinach, and makes up about 90% of the vitamin K in a typical Western diet; and menaquinones (vitamins K2), which make up about 10% of Western vitamin K consumption and can be synthesized in the gut by microflora. The K2 form of vitamin K is made from K1 and K3 by bacteria and other microorganisms. It can also be made in the human body through a conversion process involving K1 and K3.
In plant foods, you won’t find much preformed K2, unless those plant foods have been fermented or otherwise transformed by bacteria or other microorganisms. Certain microorganisms can convert K1 into K2.
Menaquinones (MK-n: with the n determined by the number of prenyl side chains) can also be found in the diet; MK-4 can be found in animal meat, MK-7, MK-8, and MK-9 are found in fermented food products like cheese, and natto is a rich source of MK-7.
Vitamin K is an essential nutrient necessary for responding to injuries – it regulates normal blood clotting. In addition, by assisting the transport of calcium throughout the body, Vitamin K is also helpful for bone health: it may reduce bone loss, and decrease risk of bone fractures. Vitamin K2 is known as a procoagulant and may also be useful for atherosclerosis and heart disease. When brain cells do not have enough energy, they begin to die off, disrupting signals and causing movement impediments.
Vitamin K1 and K2 Can Help Prevent Diabetes
The review, published in Nutrition and authored by Prasenjit Manna and Jatin Kalita from the CSIR-North East Institute of Science and Technology in India, concludes that naturally occurring Phylloquinone (K1) and Menaquinones (K2) are beneficial among people with metabolic syndrome and at a high risk of type 2 diabetes.
Manna and Kalita added that the benefits observed for phylloquinone were observed at significantly lower doses of menaquinones, suggesting that menaquinones may be more effective than phylloquinone in reducing the risk of type 2 diabetes.
“This review for the first time provides an overview of the currently available preclinical and clinical evidences about the beneficial role vitamin K supplementation on insulin sensitivity and glucose metabolism, which may be helpful for the development of a novel adjuvant therapy to achieve better control of glycemia and improve the lives of the diabetic patient population.”
The Awareness of Vitamin K2 and its benefits grows
Dr Hogne Vik, stated that clinical trials show both vitamin K1 (phylloquinone) and vitamin K2 as MK-7 (menaquinone-7) are beneficial for patients with metabolic syndrome and high risk of type 2 diabetes (T2D), but note that the risk reductions were found for lower intake of K2 than K1, suggesting that vitamin K2 could be more effective. The authors also suggest that the vitamin K-dependent protein osteocalcin (OC) is important in the regulation of glucose metabolism.
“It’s good to see that great work continues and that the awareness of Vitamin K2 and its benefits grows, yet more has to be done. This paper should be used to support future research programs to further confirm and explore the vitamin K effects for risk reductions for developing diseases, and also identifying diseases where vitamin K could be the preferred action over a drug.
Commenting on the potential mechanism(s) of action for improving insulin sensitivity and glucose tolerance, the authors noted several possibilities including carboxylation of vitamin K-dependent protein, regulation of adipokine levels, anti-inflammatory activity, and lipid lowering effects.
“However, there is so far no mechanistic study describing in detail about the molecular mechanism underlying the beneficial role of vitamin K in insulin sensitivity and glucose metabolism,” they added. “Thus, future studies with diabetic animals and diabetic patients are needed to dissect the molecular mechanism underlying the beneficial function of vitamin K in improving insulin sensitivity and glucose metabolism in diabetic pathophysiology.”
Combining Calcium and Vitamin K2
The type of minerals in Calcium and K2 formulas determines the absorption levels: Opti-Cal/Mag with Vitamin K2 is a co-enzyme complex, heat-stabled molecules that must be associated with another enzyme for them to perform their function in the body. It is necessary in the utilization of vitamins and minerals for proper delivery to the cell nucleus. One study found that Opti-Cal/Mag complex is 8.79 times more absorbed into the blood than calcium carbonate and 2.97 times more than calcium gluconate.