NPPB and heart failure: In addition to micronutrient dosage, other parameters have been explored to facilitate the interpretation of micronutrient deficits: for example, (1) C reactive protein (CRP) to detect inflammation, which can influence selenium, vitamins B9, and B1 levels; (2) Brain Natriuretic Peptide (BNP) and left ventricular ejection fraction (LVEF), markers of heart failure, may be associated with selenium deficiency; and (3) GGT and alkaline phosphatase are markers of liver cholestasis that can alter copper blood level.