In doing my final search for studies on vitamin K2 and cardiovascular disease (CVD), I came across one on type 2 diabetes (1). Since diabetes can be fairly related to CVD, I decided to review it.
As with most of the studies on vitamin K2, the population was from The Netherlands. And just like the research on stroke, it was using the combined data from the Prospect and MORGEN arms of EPIC. After excluding people with prevalent diabetes at baseline, they had a study population of 38,094 men and women. The average daily intake of vitamin K2 was 49 µg in the highest one-fourth versus 15 µg in the lowest one-fourth.
After a median follow-up of 10.3 years, and adjusting for many variables (2), in comparing the highest intakes to the lowest, there was a trend towards a lower risk of diabetes, although the finding was not statistically significant (.80, .62–1.02). When looking at what effect an increase of 10 µg had on the risk of diabetes over the entire range of intakes, there was a borderline statistically significant beneficial association (.93, .87–1.00; p < .038).
The researchers had a number of guesses as to why vitamin K2 might be protective against diabetes, all of which amounted to an indirect effect on insulin sensitivity. They also pointed out that the fact that vitamin K2 comes from animal products might have hidden the true strength of a beneficial effect on type 2 diabetes.
1. Beulens JW, van der A DL, Grobbee DE, Sluijs I, Spijkerman AM, van der Schouw YT. Dietary phylloquinone and menaquinones intakes and risk of type 2 diabetes. Diabetes Care. 2010 Aug;33(8):1699-705. doi: 10.2337/dc09-2302. Epub 2010 Apr 27. | link
2. Variables adjusted for: age, sex, waist circumference, smoking status, physical activity, hypertension, education, alcohol consumption, total energy intake, saturated fat, polyunsaturated fat, monounsaturated fat, protein, fiber, calcium, vitamin C, and vitamin E.