It's true that the gut bacteria produce vitamin K2 from vitamin K1, but we do not absorb much of that K2 - the gut bacteria keep it for themselves.
I once emailed Dr Cees Vermeer, the scientist leading research into vitamin K2 and asked him what people did before supplements as surely people weren't deficient. He told me that before the advent of refrigeration food was often slightly 'spoiled' and the bacteria which 'spoiled' the food made vitamin K2. People who eat more fermented food, like certain cheeses, or that Japanese natto, have higher levels of K2 than people who don't eat those foods.
They probably have higher levels of Vit K2, BUT If the other people aren't deficient, then its just extra and not really needed.
As for Valve calcification, being related to diet or supplements, I guess it MIGHT be in some cases, especially in native valves that slowly stenosis over time and are usually the cause for elderly people needed new valves.
But for tissue valves where the main build up causing the stenosis, is made up of different things (apatite) than calcification in the arteries, my guess would be that isnt dependent or have much to do with Vit K 2 defieciency, since the main group of people who go thru tissue valves the quickest are the younger, (teens,20s-30s)patients, so I doubt they all are deficient in Vit K1 or 2. Many people including doctors that treat mainly children and young adults believe the "calcification" of tissue valves or grafts, conduits etc, is probably related to the body's ability to grow or heal bones. Which makes more sense to me since younger people who are still growing or at ages where broken bones tend to heal quickly and usually have very good bone density, usually are the age group who tissue valves USUALLY last the shortest time in, but elderly people 60s and up who usually have a harder time with bones healing or have low bone density or even osteoporosis and past menopause in females, are the age group that tissue valves tend to last decades in. So I would tend to believe that ( bodies ability to grow or heal bones) plays a larger role in tissue valve's longevity than how much vitamen K (1 or 2 since the body needs k1 to make k2) a person takes in.
I also have wonderred if the fact normal flora that convert k1 to K2 often get wiped out with antibiotics, IF that plays a part in why people on Coumadin really have to watch their INRs while on antibiotics.
ps
When rereading the first post, since they had him add K2 and D and STOP his calcium supplements, to me that makes it tougher to say 1 change made a difference, unlike most studies where just 1 thing is changed, or maybe multipl arms where a combo may be changed in 1 arm, 1 thing in another arm and no changes in the control.
"Because of his aortic valve issue, I suggested that, in addition to the 10,000 units of vitamin D required to increase his 25-hydroxy vitamin D level to 70 ng/ml, he also add vitamin K2, 1000 mcg per day, along with elimination of all calcium supplements. (I asked Don to use a K2 supplement that contained both forms, short-acting MK-4 and long-acting MK-7.) "
