It is but K2 absorption is complex as well. It’s not quite as straightforward as something like salt and potassium intake etc.
Additionally there’s just so much about gut health that we operate largely out of ignorance on. Even simple things like the prevalence of intestinal and other parasites in North America etc are tinged with ignorance or bad backing data
Looking at you, probiotics. Actually, I was really impressed at how far we've come in probiotics after attending supply side west. Lots of focus on how to target specific outcomes through supplementation of specific bacterial strains. But still, there's a lot we do not know
I have no idea how complicated the gut / flora dynamics are in response to such a treatment.
E.g., maybe adding bacterium A triggers a die-off of bacterium B, and thus a population explosion of bacterium C, causing reduced diarrhea, leading to growth of D, causing inactivation of E, ...
Tangentially related, but there is pretty strong evidence that having some types of gut parasites is actually largely a benefit due to the way they modify our immune responses.
Edit: are there any a prioris you can offer as a basic jumping off point inline with your commentary?
It is very personal, and as your body makes D3 when exposed to sunlight it also varies significantly with the seasons.
Edit: aha, thought experiment ;) just talking about this earlier
Edit: to child reply: surely it can't be that touchy or non-robust. Not asking for medical advice ;) just give me a floor to investigate
https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessiona...
(I know this is a cliche response, but it seemed worth mentioning.)