Deficiency ?
I’m wondering whether thiamine deficiency/functional B1 deficiency could be a significant part of my long-term severe fatigue and heavy-body feeling (even turning over in bed can feel physically difficult). Looking back through my tests, a FunctionalDX blood panel in 2020 actually flagged an 80% thiamine need, based partly on fasting glucose 6.19 mmol/L, anion gap 18.5 and CO₂ 23.6. My HbA1c was 5.69%, C-peptide 1.10 nmol/L and fasting insulin 79.87 pmol/L, and the report also flagged blood-sugar/metabolic dysregulation. On an OAT in 2023 my urinary lactate was only 6.9 (lab range ≤48), but on the 2024 OAT it had risen dramatically to 326 mmol/mol creatinine; pyruvate also went from 0.81 to 6.7. By Sept 2025 my CO₂ had fallen to 20.9 and anion gap risen to 20.9, fasting glucose was still 5.68, and the report again gave me an 80% thiamine-need score. I’ve also historically eaten a fairly high-sugar/high-carb diet and my health/energy deteriorated substantially after surgery several years ago. I realise none of this proves B1 deficiency, but the lactate/pyruvate + glucose + CO₂/anion-gap pattern has made me wonder about impaired thiamine-dependent carbohydrate metabolism/PDH. I’m currently titrating thiamine HCl low and slow and am at 300 mg/day (100 mg three times daily), alongside a calcium/magnesium supplement and a non-methylated B-complex. I previously tried one capsule/day of TTFD for perhaps ~2 months but noticed no improvement and stopped; I don’t remember the exact dose. I’m considering trying benfotiamine and/or TTFD again after giving HCl a proper trial. For those knowledgeable about high-dose thiamine: does this biochemical pattern look suggestive to you, which form would you favour, how would you titrate it, and what cofactors/labs would you monitor?