What Do You Make Of This MK7 Vs MK4 Study?

[maillol]

Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women

This study seems to show that MK7 is more bioavailable than MK4.

MK4 intake did not raise serum MK4 level at all.

I take MK4 myself but the study is interesting.

Perhaps MK4 is fully metabolised before the first reading at 2hrs after administration? Perhaps MK7 floating around in the blood is not a good thing?

We conclude that MK-4 present in food does not contribute to the vitamin K status as measured by serum vitamin K levels. MK-7, however significantly increases serum MK-7 levels and therefore may be of particular importance for extrahepatic tissues.

I find this hard to believe as the only food that really contains MK7 is natto which is pretty obscure. They are saying we do not get any MK4 from milk, cheese, eggs or liver?

 

[LeeLemonoil]

Lots of longer MKs in animal foods, including meat. K1 in green plant foods. We get enough Vit K, it doesn’t matter which

 

[maillol]

Perhaps it is the case that mk7 is much more bioavailable than mk4 and that is the reason mk4 is often taken in much higher doses. I've seen haidut say that mk7 has an identified toxic dose but mk4 does not. Could it be that this is simply because mk7 is far more bioavailable?

 

[LucH]

Vitamin K2 MK4 is almost completely metabolized in the intestine, and the absence of K2 Mk4 in the bloodstream is no evidence of the superiority of K2 Mk7 - as some studies suggest (19); it just takes longer to be metabolized (up to +/- 72 hours). So, if you are presented with a graph establishing a higher rate of presence of Mk7 in blood serum, this is not a "proof" of better efficacy, or even bioavailability in some cases, as some sources claim ( * 19) or relay it (* 20) In the latter case, it will just be necessary to specify what will be the target and the therapeutic objective.
See Absorption de K2 for details (in French) but with links for sources in English.
=> Absorption, storage, bioavailability and target tissues of menaquinones (K2)
Vitamin K therapeutic dosage
Examples for buying vitamin K2