After some chronic infections and stress, I notice I have many issues with digestion, CNS, temperature, fatigue etc. Most times I take 100mg of B1 (TTFD) with niacinamide and magnesium, my brain fog clears, and I actually feel warm all over and sweating (in last year I have rarely even had a good sweat). Gonna try if taking this combo for 2 weeks restores my normal function. But its really a night and day difference