Natto is not "normal". It is an acquired taste. The acquisition of said taste is a difficult, nauseating, and extremely stinky path. Besides that, most of the vitamin K from natto is as MK-7.
Animal-sourced vitamin K is mostly menatetrenone (aka menaquinone MK-4) whereas vitamin K from fermentation bacteria is various lengths of menaquinone, of which only MK-4 and MK-7 have good vitamin K activity in humans, and the MK-4 form is usually nearly absent. Plant-sourced K is as phylloquinone, which has to be converted to menatetrenone in the body.
So also-good sources are egg yolks from free-ranging, pastured laying hens and butter from free-ranging, pastured dairy cows. Basically, you need to eat parts of animals that were raised by traditional, non-battery farming, particularly the livers and adipose tissue. Poultry animals such as geese, chickens, and ducks are good for this. Apparently, the oil from rendered emu fat is also high in vitamin K.
Cheeses have some MK-4 from the milk and some MK-7 from the bacteria, but a lot of their K is in less easily assimilated forms. That's probably good enough unless you have some rare and nigh-undetectable enzymatic deficiency that interferes with conversion of MK-9 to MK-4, or something.
I suppose that if you force-fed some geese a bunch of natto, and then mashed up their livers into a paste, that would be a great vitamin K pate. I think I'd rather just swallow a pill.
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.
