blood mineral amount blood sodium amount CMO:0000060 CMO:0000499 CMO:0000500 EFO:0009282 The proportion, quantity, or volume in whole blood, serum, or plasma of this metallic element, the most plentiful extracellular ion in the body and the principal determinant of extracellular fluid volume. Trait.ontology VT:0001776 blood sodium level circulating sodium level blood electrolyte amount