Thiamine is an essential vitamin for turning food into energy and keeping nerves, brain, and heart working. Its clearest value is preventing and reversing true deficiency — safe, cheap, and often quickly effective. Whether extra amounts help already well-nourished adults, including for slowing aging, remains genuinely open, though the risk is very low. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Whole-blood thiamine diphosphate | ~90–180 nmol/L | Most direct measure of body thiamine |
| Erythrocyte transketolase (TPP effect) | <10% (aim); <15% normal | Functional thiamine-enzyme activity test |
| Magnesium (serum / red-cell) | 2.0–2.4 mg/dL | Required to activate thiamine |
| HbA1c | <5.4% | Glycation burden for benfotiamine goals |
| Fasting glucose | 75–85 mg/dL | Metabolic context for diabetic-goal use |
| Serum lactate | <1.0 mmol/L | Reflects impaired thiamine-dependent energy metabolism |
Cadence: Baseline before starting; reassess at ~3 months, then every 6–12 months (or sooner if symptoms change)