Foie gras is not "normal", because it's very expensive and its production inhumane. And I did not call Natto normal, if you read my comment carefully. It's not that easy to acquire, and as you said, it's disgusting.
Most pills/drops you would prefer over foie gras are mostly made from Natto (MK-7) btw.. there are some supplements with MK-4 but those are rare and quite expensive.
I meant "normal" in the sense that it contains the animal form of vitamin K (K2 MK-4) rather than bacterial (K2 MK-7) or plant (K1) vitamin K.
Foie gras is nauseating for a completely different reason than natto. As actual food goes, I'd rather eat the pastured eggs and butter, even though they are also rare and expensive in US supermarkets.
It doesn't help that the supplement industry is loaded to the rafters with hucksters and scammers, but you can get a year's supply of pills labeled as 5 mg MK-4 for $90. It'd be hard to tell whether that's really what's in them without engaging a testing lab at additional expense.
Most pills/drops you would prefer over foie gras are mostly made from Natto (MK-7) btw.. there are some supplements with MK-4 but those are rare and quite expensive.