Vitamin K2 and Stroke
I was getting ready to publish my conclusions regarding vitamin K2 and cardiovascular disease and decided to check PubMed one last time to make sure nothing had come out recently. Sure enough, there was a paper on vitamin K2 and stroke from December!
This study combined the data from the two Dutch cohorts of EPIC, Prospect and MORGEN (1). After excluding people with prevalent stroke or cardiovascular disease at baseline, they had a study population of 35,476 men and women. The average daily intake of vitamin K2 was 49 µg in the highest one-fourth versus 16 µg in the lowest one-fourth.
There was no association found between vitamin K2 and incidence of stroke either with all stroke combined, or with ischemic stroke and hemorrhagic stroke analyzed separately. None of the vitamin K2 sub-types were significantly associated with a reduced risk for stroke.
The researchers considered this finding to be in contrast to some previous population studies that found fermented dairy products to be associated with a lower risk of stroke.
They also pointed out that recent research has suggested that artery calcification (which may be associated with lower intakes of vitamin K2) may not be a cause of stroke as it is for heart disease, and that might explain some of the inverse associations found between vitamin K2 and heart disease whereas none was found for stroke in this study.
This was the only study they, or I, are aware of examining the association between vitamin K2 and stroke.
References
1. Vissers LE, Dalmeijer GW, Boer JM, Monique Verschuren WM, van der Schouw YT, Beulens JW. Intake of dietary phylloquinone and menaquinones and risk of stroke. J Am Heart Assoc. 2013 Dec 10;2(6):e000455. | link