Folic Acid, FIGLU, and Thiamine

Hi guys,

So I have been doing so much better these last two weeks after integrating benfotiamine in place of thiamine HCL. I had been taking 100 - 150mg of Thiamine HCL for over a year and my recent Nutreval test showed high thiamine deficiency, high biotin deficiency, and high folate deficiency (through very elevated FIGLU, which I believe means folinic acid deficiency, not methylfolate). I also did a comprehensive blood panel through Wellnessfx which showed very high Folic Acid levels (16.1 ng/mL). I am homozygous 677t MTHFR mutation and homozygous SLCA1 mutation (folate carrier) and had been taking methylfolate at the time (1000mcg/day). I have been riding the rollercoaster of experimenting with folate with its countless side effects. I have noticed as of late that if I take the benfotiamine in the morning and then wait to take all the other Bs at lunch (methylfolate + folinic acid product, b6 as p5p, active riboflavin, and then adeno hydro b-12), I do not get the brain fog. I have studied the other thread about thiamine and methylation, but could this be a fix? Dr. Lonsdale who spent his career on thiamine brought up a connection about unbalanced thiamine levels and high folic acid in the blood. Not very much info on b1 as a cofactor for folate.

"The chemist explained that vitamin B-1 is a co-factor in utilizing folate. Perhaps, if B1 were deficient, the underutilized folic acid would back up in the blood. Dr. Lonsdale confirmed the theory by prescribing a large dose of B1, along with a B-complex.Not only were the youngster’s folic acid levels normal upon retesting, but also his lymphatic condition significantly improved."


Any help on this :(? I get this terrible brain fog every day the Bs are involved. My theory on Thiamine before Folate does not work.

My latest theory, is perhaps I am not taking enough Folate to balance the high levels of Bs? If I take Niacin or Thiamine on there own, I get the brain fog/spacey feeling/can't read or accomplish anything. If I take a folateless b complex like Seeking Health B Minus, I get the brain fog. If I take folinic or methylfolate the fog lifts for 15 minutes and then comes back. My theory is maybe I can tolerate high dose B vitamins in a complex to correct my biotin and thiamine deficiency, but only if I'm taking crazy high amounts of folate like 5mg/day or more?


Retiring Night
Ik waak up
I am tired now, forgive that I havn´t read through your posts.

I take B5, B7, B2 and B1 with good effects (supporting the TCA cycle)

I must not take B6 and B9. Really not take (probabaly b/c they would serve amino acid metabolism?)

B3 announced itself as bad as well, don´t want to try it again rn.
(why? maybe b/c tryptophan had potentially not only good effects, and these ones only in combniation?)

For some time I took a combo of all B´s, wasn´t good nor bad.

In addition I change the placement of metals, but taking them in (in chocolate) only under good circumstances.
I will give a link in my signature. Who knows, maybe it could help.

I think these strange feelings in at least my brain mirror
actions of nerves also as they are bad (or too good) supported by vit´s and metals.

I need to look at vitamin carriers, it will be interesting. Thanks for hinting.
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