Which word part forms the core of a medical term?

The word root is the word part that is said to be the core of the word and contains the fundamental meaning of the word. It is important to note that each medical term will contain one or more word roots.

Cacium and phosphous build strong and flaxble bones. a diet that lacks these nutrients can lead to osteoprosis should be it hopefully

Ithink it is the last one sorry if i’m wrong