You won't find it in traditional drug stores. Try The Vitamin Shoppe and maybe GNC or a "health food store". If they don't carry it they might be able to order for you.
Most folks tend to take much larger doses than you'll get at most drugstores, for those you'll have to look to specialty health stores or online. I'm taking 5mg K2 (MK4) from Carlson Labs now, pretty cheap on Amazon.
If you eat dairy, you could try a natural high source of K2 http://www.thehealthyhomeeconomist.com/gouda-the-nutrient-dense-cheese-of-choice/
Both pomegranate and cashew nuts have high amounts of vitamin K. Don't know if it is K2 though.... Sweet chestnuts also contain, some, as do avocados and kiwi fruit.
I really like this combined Vitamin D & K1 & K2 supplement: http://www.naturalhealthyconcepts.com/vitamin-d-supreme-DFH60-p-designs-for-health.html?currenttab=2
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