I came across this post, credit to William Wallace, PhD which got me thinking about Thiamine one of the many supplements people take without testing and the lack of meaningful testing:
Every molecule of glucose you eat has to pass through one enzyme to become ATP. That enzyme is pyruvate dehydrogenase. Its cofactor is thiamine.
Glycolysis breaks glucose down to pyruvate. That happens in the cytoplasm and doesn’t require thiamine. But pyruvate can’t enter the mitochondria as acetyl-CoA without PDH converting it, and PDH can’t function without thiamine pyrophosphate in its active site. If thiamine is missing, pyruvate gets shunted to lactate instead. The citric acid cycle starves. ATP production drops. Lactate accumulates.
This isn’t just a textbook pathway. Hanninen et al. measured thiamine status in 100 hospitalized heart failure patients and 50 controls. 33% of heart failure patients were thiamine deficient vs 12% of controls. A well-established driver: loop diuretics increase renal thiamine clearance. Nearly every heart failure patient is on one. Thiamine is water-soluble with total body stores of only 25-30 mg. Without daily replenishment, stores can be depleted in as little as 2-3 weeks.
This creates a plausible vicious cycle. Heart failure patients are put on furosemide. Furosemide depletes thiamine. Thiamine deficiency impairs cardiac energy metabolism. Cardiac function worsens. The diuretic dose goes up. More thiamine is lost. Supplementation trials have shown mixed results on ejection fraction, but the metabolic logic is sound and the deficiency is measurable.
Beyond heart failure: diabetes is independently associated with low thiamine status. Alcohol impairs thiamine absorption and increases excretion. Bariatric surgery reduces absorptive surface. High carbohydrate intake increases thiamine demand because carbohydrate metabolism is the pathway most dependent on it.
Thiamine status is not part of standard blood panels. If you’re on a loop diuretic, managing blood sugar, or recovering from surgery, it’s worth asking about.
Hanninen et al., J Am
Coll Cardiol, 2006.
The above which led to the discussion and a specific lab testing, which I’ll link here rather than give an interpretation.
What are your thoughts on Thiamine, it’s rank in your health concerns and the relevance to the lab test mentioned?