I never got the hang of knowing when I used up my B12 as some experience. Likely as I was also B1 deficient. The only way to determine if you are B1 deficient is to do a trial. The blood test is useless.
Functional Deficiency of a Vitamin may be nothing more than a work around for not understanding that some organs can be deficient and the testing is inadequate to determine that and the only way is with a trial based on symptoms.
I have not experienced what I knew as fatigue/brain fog since I started injecting three times a day and taking sublingual Adeno . I now experience what I term brain haze/being off. That has improved dramatically in the last 14 days I have been taking 50 mg P-5-P and 300 mg Benfotiamine B1 three times a day.
When I started this post I was thinking I sometimes use up my B1 between doses. That does happen but in this moment I think my getting slightly was not from getting more sun and my body adjusting to the B1 and beleve t is from under supplementing B1. I am more and more leaning towards reversing out and the paradox of feeling worse is due to under supplementing due to lack of knowledge of how to treat vitamin deficiency. I do not have a solution I just know no one else does and many make the error of under supplementing and simply waitig because that works or is acceptable to some. I have studied the methods of establishing RDA's and expect it is not scientifically sound. It was developed after WWII when science was going to be the answer to all problems. That understanding still is prevalent despite the failed results.
So I would simply increase to 4 times a day but I had scheduled my next trial to be magnesium. For many reasons none of them connected to following or hoping I can magically find what works best that is likely the best course of action.
I took B1 and B6 orally a couple of hours ago and can expect that I will be on enough to do the research I want to do to determine what form of magnesium has the most likely efficacy for me and at what dose to start. I am an active 180 pound male.