"poor bioavailability" means that a substance, such as a medication or nutrient, is not easily absorbed or used by the body when consumed or taken in. Full definition
Since vitamin B12 detoxifies cyanide by binding it and causing its excretion in the urine, this form might have very poor bioavailability in many people. (westonaprice.org)
While EGCG has proven to be powerful in vitro, poor bioavailability in the human body hampers its health and physique - boosting potential. (ironmanmagazine.com)
Some nuts contain plenty of zinc, but they also suffer from the problem of poor bioavailability. (supernaturalacnetreatment.com)