As a note: lots of sauerkraut sold in stores (at least in America) isn't actually fermented but just cabbage soaked in vinegar which is shelf stable. If you want the fermented kind, make sure you get it from the refrigerated section and check the ingredients and it should not have vinegar.
Or just make it yourself, it's dead simple to do, especially with all the silicone waterless airlocks for mason jars showing up on amazon under cheap chinesium brand names (the original masontops product was more expensive)
Looks like nori seaweed sheets, some herbs including parsley and basil, egg yolks, soybean and grapeseed oils, and cheeses contain K2 as well(in rough order of concentration).
In case anyone isn't sure about kimchi and natto every few days, but "for better cognitive ability" would be a nice excuse usable for occasional sushi rolls, stir-fries, just a bit of extra Parmesan, maybe even fries :p
