I understand. I think if you or someone else were skeptical, they'd probably be right to be. But you'd be surprised how far you can get using heuristics and experimentation with low-risk nutritional products to determine if they are beneficial or not, although any results achieved this way are understandably not very convincing to an external observer.
I think a good heuristic is if something is a very common nutritional element, then it's likely safe. Vitamin K2 in its MK-4 form is found in the cheese and meat products produced by grass-fed animals (think Netherlands, France...), while its MK-7 form can be found in certain plant-based products fermented with B. subtilis (Natto). People eat high-K2 diets around the world. It was certainly not going to kill me to try it out at a dose not exceeding what you can get from food (e.g. Natto can have 1000mcg of K2 MK-7 in a single serving!).
I also try not to take most supplements every day, because the idea is simply to top off levels of things I'm deficient in, plus to give the body some time to eliminate the supplement after using it, which reduces toxicity risks even further (turnover is an important factor), and also reduces the risks of forming a dependency (for example, I don't take taurine supplements every day, in case the body's own taurine production would get suppressed).
edit: "what to combine it with or not,"
It complements vitamin D, magnesium and calcium. I discuss this briefly in another post in this comment tree.
While I don't 'believe' every bit of bro-science I hear (as in, take all claims at face value), let's just say that I'm not very worried about overdosing most supplements and I rather try things out than spending hours upon hours reading about things I don't really understand anyway, and of which there is no scientific consensus :) Just to say, no need to convince me to try something like this :)
I just ordered a combined MK-4/MK-7 supplement, and added some vitamin D3 as well as it seems to be a good combination, so fingers crossed that I can tell my dentist the next time I go how well it works :) (for years she's been lecturing me time and time again how I should brush better, despite brushing at least 2 times a day and flossing consistently. I think she just doesn't believe me that I actually do those things).
I think a good heuristic is if something is a very common nutritional element, then it's likely safe. Vitamin K2 in its MK-4 form is found in the cheese and meat products produced by grass-fed animals (think Netherlands, France...), while its MK-7 form can be found in certain plant-based products fermented with B. subtilis (Natto). People eat high-K2 diets around the world. It was certainly not going to kill me to try it out at a dose not exceeding what you can get from food (e.g. Natto can have 1000mcg of K2 MK-7 in a single serving!).
I also try not to take most supplements every day, because the idea is simply to top off levels of things I'm deficient in, plus to give the body some time to eliminate the supplement after using it, which reduces toxicity risks even further (turnover is an important factor), and also reduces the risks of forming a dependency (for example, I don't take taurine supplements every day, in case the body's own taurine production would get suppressed).
edit: "what to combine it with or not,"
It complements vitamin D, magnesium and calcium. I discuss this briefly in another post in this comment tree.