A fat-soluble form of vitamin B1 that reaches the brain more easily than the ordinary vitamin. Its most credible benefit is a modest, short-term easing of fatigue, especially fatigue tied to a known cause. Effects on memory, mood, and nerve symptoms stay unproven. Generally well tolerated short-term; the main worry is mood elevation in susceptible people. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Whole-blood thiamine / erythrocyte transketolase | Within or above mid reference range | Confirms whether a true thiamine deficiency underlies fatigue |
| HbA1c | < 5.4% (functional) | Contextual marker in the diabetic-neuropathy setting |
Cadence: Reassess symptoms and mood at 1–2 weeks and at 4 weeks; if used intermittently long-term, review at each cycle or roughly every 3–6 months.