Okay I think I've got this shit figured out.
MK4 selectively accumulates in the brain, pancreas, sternum and salivary glands. Following my OD with MK-4 three years ago, I had very bad anxiety (brain), bad digestion (pancreas), chest pain (sternum), and eventually teeth pain (salivary glands).
Contrary to popular belief Vitamin K's primary mechanism isn't in calcium retention. Vitamin K is used for gamma-glutamyl-carboxylation, which chelates serum calcium between two protein heads and deposits it in long bone (osteocalcin) or uses that calcium to drive thrombosis. There are also lots of GLA proteins in mitochondria, and the suggestion is that calcium may promote metabolic activity in mitochondria.
So Vitamin K is a calcium chelator. It does not deposit calcium into most cell types. It binds it to GLA proteins and activates them. So it actually causes localized decalcification and hypocalcemia. If it accumulates in the sternum, you get sternal pain, which I think actually stems from decalcification of the sternal cartilage, which causes hypermobility of the rib cage and pain in the costosternal joints. I've had two chiropractors see me since this happened, and both said that my rib laxity was crazy (never had any chiros say that beforehand). If it accumulates in the salivary glands, it chelates salivary calcium (saliva has a high calcium content to keep teeth mineralized, so without calcium you get teeth pain and possible dental carries). If it accumulates in the pancreas, you get hypocalcemia, and calcium is needed to produce protein digesting enzymes (which is why I couldn't digest any proteins without some kind of horrible skin reaction until I fixed my digestion). And if it's in the blood, it will cause thrombosis - thickening of the blood. In the brain though, you actually get higher sphingolipid content and better myelination. Hypocalcemia in the brain would make for more pronounced stress response, but I hate to simplify the brain - I'm sure it is much more complex depending on the areas most effected and most likely to retain K2 (which we don't know yet). Increasing dietary calcium wouldn't actually increase intracellular calcium, since Vitamin K is present in the blood - dietary calcium would first hit the serum where it would increase thrombosis (clotting, blood thickening). Then whatever calcium is leftover would go into normal calcium processes.
Unfortunately for those of us that took MK4 - MK4 is stored longer in the body than all other types of vitamin K. All we can do is take strategies to mitigate some of these problems until we work the MK4 out of our systems.
Chris Masterjohn did publish a paper on the reciprocal relationship between Vitamin D and K, saying that the symptoms of excess vitamin D may be entirely due to depletion of Vitamin K. I've certainly had a lot of success with sunlight, and I've replaced that with about 10,000iu/day of vitamin D since it's gotten colder and less sunny with good effects (although not as good as sunlight directly on the sternum). I think vitamin D is central to depleting vitamin K2 faster, and localizing it to the sternum where most of the symptoms stem from would be ideal. Vitamin D will also upregulate osteocalcin synthesis, which vitamin K carboxylates to carry calcium into the bone, so it uses up vitamin K away from doing damage in other areas (sternum, salivary glands, brain).
I think in terms of mitigating side effects, low-dose aspirin may be a good temporary strategy in preventing thrombosis and keeping the blood thin. I've been using xylitol mints with calcium lactate to get rid of teeth pain, and they've worked magnificently (I take about 4-6/day and use them as a mouth wash - never swallowing them). I think avoiding calcium as much as possible isn't a good strategy long term. I did it for over a year, and things got better for a while, but much later on some symptoms started getting worse (primarily teeth pain). I've since re-introduced small amounts of calcium and dairy and things have been good. I do notice my heart has to work harder when I eat a lot of dairy - I think this is from the increase in coagulation (clotting) that comes from excess calcium. As the blood thickens, the heart needs to pump much harder to push things around. I've found taking consistent low-dose aspirin prevents this completely. Aspirin stops the conversion of vitamin K epoxide back to it's active form, so it's excreted fast.
As far as anxiety, I've found that has gotten much better since controlling my other symptoms. It will peak in occasionally, and I'm definitely more hyperactive overall now than when I was younger. Which is actually welcome, because life is busy as hell and I have the energy to do things without always needing coffee like everyone else I know. I've found that any residual anxiety I've had has gotten better with adding calcium back in my diet as well.
In line with all of this, I've recently cut out foods high in Vitamin K. So no leafy greens mostly. Haven't noticed much of a change honestly, probably because it's a recent change and the majority of K1 is never digested and just excreted out.
The main takeaway is to pump up the Vitamin D and sun especially, lower K intake, don't fuck with calcium intake too much (600-800mg/day is probably good), and take some low-dose aspirin. And if you experience teeth pain or dental carries, xylitol + calcium lactate mints will hold them at bay until things get better.
