Vitamin B6 status is commonly assessed using PLP concentrations as a biomarker of body stores. Broader biomarker frameworks also describe direct and functional indicators of B6 status, which helps clinicians interpret results in context rather than as a single number (Ueland, 2015). For owners, the practical point is that testing is most informative when paired with a diet history, appetite timeline, and any gastrointestinal signs that could limit absorption or intake.
Before a visit, gather labels or photos of all foods, treats, and supplements, plus the exact amounts offered. Note when appetite shifted, whether vomiting or diarrhea occurred, and whether the cat is on any medications that changed recently. This preparation turns “maybe a vitamin issue” into a structured conversation about intake, digestion, and realistic next steps.