Im going to lump a few studies together here. One will also show why you cant supplement this directly when it comes to k2 or menaquinone.
Vitamin K epoxide reductase regulation of androgen receptor activity
Reduced vitamin K synthesis linked to heart disease
Vitamin K2 intake from diet did not appear to contribute to subclinical atherosclerosis, suggesting that small intestinal dysbiosis and low bacterial vitamin synthesis were fundamental.
One example of possible dysbiosis, how microbes compete.