I've read about that and its something i need to look into. I did have a vit D deficit a few years ago and was prescribed it.
Is the need to balance it with K2 only relevant to extremely high doses or to normal doses? The consensus with the NHS is that no-one in the UK gets enough vitamin D over the winter months, its just not sunny enough and they recommend basic supplementation.
This might suggest that it is not in fact necessary to supplement vitD with vitK unless D is taken in very high doses? It is confirmed that we need vitamin D but if vitamin K is not a normal part of diet, how can the synergy occur naturally?
I'm currently looking into restoring my gut biome. It's pretty complicated. TBH I don't put much credence in people's testimonials, as they all seem to occur when someone is trying to sell something. I definitely believe the biome is essential for all sorts of reasons to maintain physical and mental health, but I'm not convinced by the idea of going without vitamin D in food. And sorry, but going without sunshine? That just made me laugh. Though ofc maybe this is temporary regime to eliminate these biofilms so maybe that makes more sense. Still, that all sounds a bit extreme and I have a tendency to think a more balanced approach is reasonable.
I've never heard of Natto. I shall have to look into that for sure.
I had read that and forgotten about it. Now I shall change when I take it, thanks!
I too believe that all these things act in concert and concentrating on any one element is liable to either fail or cause issues. That's why I'm trying to eat as wide a range of vegetables as possible, cooked and uncooked, at least as a nutritional starting point. I've been trying to repair my gut biome and have ended up taking all sorts of things, prebiotics, flax, medication, different sources of soluble and insoluble fibre in food, probiotic supplements, all to try and act in concert to give the epithelial cells of the colon wall more butyric acid. Probiotics are odd, because I'm not convinced that they survive into the gut. I've been experimenting with different strains, delivery and taking with resistant starch or on an empty stomach to see what might work. I'm starting to thing that supplementation might not be the most effective method for probiotic enhancement.
I've made notes of your comments to alter some of my behaviour and also to do some more research, so thank you.
I'm not married to any of these concepts that I read online, so I'm just pointing out some things to potentially consider. And, just to underscore this concept of being unencumbered, I think sunshine is extremely healthy for almost everyone. For example, I have vitiligo - "the Michael Jackson disease" - and the sun damages and physically pains my skin, so I have to drastically limit my exposure. My ex-wife had lupus and had to avoid the sun, as best she could, or else it triggered flare-ups. These are the types of exceptions in my mind.
My understanding from some of these experts is that it's recommended to balance the vitamin D with K2 when supplementing with any dosage. I don't recall uncovering how exactly this was determined. I've tried chasing down original sources for some of these types of claims in the past, and it turned out, in some cases, to be going down a big and time consuming rabbit hole with inability to locate any original source. In those instances, I assumed what I was reading had a huge chance of being complete BS. This is extremely problematic with some of these online health experts' claims.
It seems intuitive, as you astutely observed, that since vitamin K2 is hard to come by naturally through dietary means, then how critical is it to the body? My conclusion, correct or incorrect, was that some believe K2 comes into play with the supplementation of vitamin D, as though artificially acquiring vitamin D through supplements caused the need for vitamin K2. Is this accurate? Who knows! I highly doubt there will ever be a twenty year long, randomized, double blind, placebo controlled study to try and better figure it out. However, I personally decided to hedge my bet and eat natto if I take vitamin D.
Some think that natto might be a key component for some of the positive health attributes in many Japanese nationals. But, correlation is not causation, and this stuff is all epidemiological. And, if in fact natto does contribute health benefits is it from the vitamin K2, the probiotic, the phytoestrogens of the soy, plant proteins, or something else? No one knows.
The problem with most of this type of stuff is that it's based on anecdotes or epidemiological studies, at best. The variables are too complex to isolate through nutritional epidemiological studies. Nutritional science is a weak field.
There is some interesting ongoing research called the human gut project through University of California at San Diego. They are testing and charting peoples' microbiomes through fecal samples to better understand diversity of bacterial cultures within peoples' microbiomes. For something like $100 US, one can have their complete microbiome charted to see how they compare with others. I finally decided to get charted last spring, but saw Covid necessitated a reallocation of testing resources, and studies have been temporarily halted. Not sure if these have resumed yet.
The human gut project is interesting particularly for someone like myself, who has fibromyalgia, since researchers have identified a divergence in 19 (?) different bacterial species within the microbiome of those with fibromyalgia. Some species are tested higher and some species are tested lower in those with fibromyalgia compared to the general population.
This information about my microbiome composition would serve for curiosity more than anything most likely.
Dietary interventions are stated to somewhat alter the microbiome, based on what I read from the scientist, who founded the human gut project. However, the scientist said the change is transitory and microbiomes revert back once one returns to eating their regular diet.
I've read some opinions that supplementing probiotics has a transatory effect and that the supplements are incapable of latching on and taking up residence in the gut. I've read some researchers speculate that probiotics somehow are able to communicate with one's existing microbiome through this transitory process. Do I believe this? Possibly. But, how and when would this be proved? Some researchers are starting to believe that species of bacteria communicate with one another inside the gut, and that species form biofilms to protect themselves from the immune system and from competing strains of bacteria. Maybe?
But, desperate times call for desperate measures, so pass me the natto.