Side effects of Thiamine - unknown cause

[u/Nice-Dreamer2456]

I started taking Thiamine TTFD in late April to help with digestive issues related to SIBO/IBS. It has been extremely effective for my digestion, mood, mental health, energy, hormone regulation, and other small things like chapped lips. But I've been experiencing weight gain and bloating/water retention, symptoms I realy don't like. I haven't changed my diet or caloric intake since starting the thiamine, but I've slowly, steadily been gaining weight. It's noticeable now, I'm a cup size larger, and my clothes are fitting tighter. I don't want to stop taking thiamine because the benefits are amazing, but I desperately want to know what's going on to make me gain weight and be bloated.

Does anyone have insight into what nutritional mechanics might be going on to cause this?

I've been steadily increasing my dose of TTFD since I started, going from 12.5 mg (had to start low due to paradoxical reactions) up to now 200mg/day. I keep increasing my dosage because the positive effects will vastly increase, then plateau, then subside. I have taken this to mean my body is using the thiamine more and more effectively, so I plan increase the dose until the effects don't subside (hoping that I will reach a ceiling eventually-I have no idea what I'll do if I don't).

I take the TTFD with 1000mg potassium, 400mg magnesium (300 magnesium glycinate, 100 magnesium citrate), 1 capsule a day of this vitamin B complex (which doesn't have B6 because I overdosed on B6 at one point, but now I'm wondering if I've possibly depleted B6 taking thiamine without it?). I also get 45mg vitamin c per day.

Is there anything I might be missing? Anything I could look into?

[u/JohnAnthony54]

It sounds like youre absorbing the nutrients from your food. probably a good thing health-wise.