By Mark Lange, PhD
There are two main forms of vitamin K: phyloquinone (vitamin K1) and menaquinones (vitamin K2). Vitamin K1 is found in green leafy vegetables and vitamin K2 can be synthesized in the gut by microflora. Menaquinones can also be found in meat and fermented food like cheese and natto.
The review concluded that naturally occurring vitamins K1 and K2 are beneficial to people who have metabolic syndrome, with a high risk of developing type 2 diabetes. The risk reductions were greater for vitamin K2 than K1. Several human studies report the role of vitamin K supplementation in improving insulin sensitivity and glucose tolerance, preventing insulin resistance and reducing the risk of type 2 diabetes.
Source: Manna, K. and Kalita, J., Beneficial Role of Vitamin K Supplementation on Insulin Sensitivity, Glucose Metabolism, and the Reduced Risk of Type 2 Diabetes: A Revew. Nutrition. Doi: 10.1016/j.nut.2016.01.011