Vitamin B1 (Thiamine / Thiamine Pyrophosphate)
Vitamin B1, or thiamine, is often measured as thiamine pyrophosphate (TPP), its active form inside cells. Thiamine helps your body turn food into energy and supports nerve and heart function.
Thiamine is central to energy metabolism, so a shortfall can affect the nerves, brain, and heart. Measuring the active TPP form gives a more accurate read of your usable status. Levels can drop with heavy alcohol use, poor nutrition, certain gut conditions, or increased needs.
A high thiamine level usually reflects supplementation and is generally not a health concern, because your body readily clears excess water-soluble thiamine. It rarely requires action on its own. Any unexpected result is best reviewed in context.
A low thiamine level suggests your intake or absorption may be inadequate, which over time can affect energy, nerves, and heart function. Certain groups, such as people with heavy alcohol use, are at higher risk.
Labs provide a normal range, and low results often prompt a review of diet, alcohol use, and absorption. A clinician can help interpret your value and next steps.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.