bioavailability

noun

Etymology: Etymology tree Proto-Indo-European *gʷeyh₃-der. Ancient Greek βῐ́ος (bĭ́os) Ancient Greek βῐο- (bĭo-)der. English bio- English availability English bioavailability From bio- + availability.

1. The extent to which a substance is molecularly available to cells and tissues in a living organism, which depends on factors such as solubility, pH level, and presence of enzymes and cofactors; for example, even if one's ingestion of vitamin B₁₂ is average/typical, one might nonetheless have B₁₂ deficiency if one has poor metabolism of this particular vitamin.
2. The extent to which a substance is molecularly available to cells and tissues in a living organism, which depends on factors such as solubility, pH level, and presence of enzymes and cofactors; for example, even if one's ingestion of vitamin B₁₂ is average/typical, one might nonetheless have B₁₂ deficiency if one has poor metabolism of this particular vitamin.

   “poor/low oral bioavailability”