Well...brain fog may be related to thyroid. If TSH > 2.0 you get progressively worse symptoms. My TSH hovers just above 2.3 and I don't have brain fog, but my TSH has been as high as 5.5 due to seasonal allergies (after a few months of allergies my thyroid wears out). If TSH gets close to 3, by then I get symptoms. I take thyroid supplements for this....my thyroid can do the job with extra nutritional help to meet the elevated demand. I do not know what else may cause brain fog but suspect (maybe I read so.ewhere?) It could maybe also be caused by inadequate methylation. You can check with a (relatively) inexpensive homocysteine test. Life Extesion used to say this should be 6.3. I have to take a lot of supplements to get mine that low, so have decided to be happy with 9.0. (I think lL.E. may now say 8 is good). To get mine In the ballpark I have to take TMG also. So... when I started Freddds protocol (before this forum), I usedto take those sublingual mB12, which brand at the time, was B Right. As well as Thorne's Basic B (which I still take) , an additional mfolate (various brands), and TMG (I started with higher dose). Please understand this is NOT my protocol because I take many other supplements and they all play a role... I have no idea what taking a few supplements here and there does to you, if you have some unknown deficiency, nor what drug interactions there might be. However, for this PART of Freddds protocol (+ TMG - not sure if that was from him) I tested high in cobalt- thus I discontinued the extra B12 and rely simply on Thorne Basic B (and a multi with active B - so I get small doses of active Bs 2x / day), 1g TMG, and 50mg P5P. I take the extra P5P to protect my kidneys but it will also improve methylation.
ALSO. I want to say I've been taking high dose B vitamins all my life to attempt to fix some kind of lifelong malaise. It didn't work but I felt it was directionally correct if I could find the missing potentiating element(s). I encountered periodic low potassium but not severe because I cannot break down many non-active b's, but my Dad was a diabetic and he gave me potassium when that happened (low dose).. I have slow kidneys because of my blood pressure, so I would not at all recommended potassium without knowing the status. But I came to this with a large protocol and most pieces of it already implemented so... never had to titration low doses or experience major jolts to my system tweaking my protocol like many here. Each person has to find their own way.
But I was raised with nutritionist Adele Davis, with the multivitamin generation, and I strongly believe in making sure all bases are covered with a multi. I f something is directionally correct but doesn't do the trick for me, I don't discard it. I think that metabolic processes take many nutrients to work and maybe I am still missing one I am unaware of.
So, for instance, I took uubiqinone for years, then tested low in it. How could this be? I switched to ubiquitol, the active form, then later discovered if your thyroid is not up to snuff you will have a hard time transforming ubiquinone to ubiquinol. There is usually a key - something not quite right about your protocol. In some cases close only counts in handgrenades...but in many cases I don't believe that. So a lagging thyroid can prolly convert SOME ubiquinone to ibiquinol, for instance. In any case, my best guess protocol that changes over time has kept me alive all my life.
I don't remember all the things that affect methylation besides B, and no doubt new ones were discovered. I believe D, some minerals, and antioxidants were also important, perhaps others. Antioxidants are always #1 to me. I have taken my whole life 2g mineral ascirbates (C), 1 g E, and later also 1g Olive LeF extract (ACE inhibitor), and 1g? Astaxanthin (I'd have to check that dose - it's from NOW). This very much also saved my kidneys from genetic high blood pressure. I hear you can over anti-oxidant. I don't think I do FOR ME. Everytime your immune system comes Into play, which includes allergies, sports,etc), you need serious antioxidants. I have noticed little cuts or abrasions hurt when I don't have enough viyami.n C. For onstance. I really don't know any other way to know...but inflammation ' isn't that the immune system causing that? I would take antioxidant for it. Just so healthy tissue is not damaged. DMSO to take down the inflammation. Idk
..your needs will differ. Sorry for such a long ramble. Going to log out until I find some other study or nutrient to raise your attention to. Take care.