many metals, including calcium, iron, phosphorous, zinc, etc. are absolutely essential for our health
Phosphorus is a nonmetal
It is not metal. The metal in our body is not pure, it's bonded to nonmetals and covalent ions. Bone, for example, is calcium metal bonded to hydroxide (OH-) and phosphate (PO4). The bonds through which metals bond to nonmetals are called ionic bonds.
Take calcium, for example. It's missing two extra electrons from having a vull valence shell (8 electrons) so this makes its outer electron shell (6/8 electrons) unstable and thus leads to the reactions that calcium goes through normally. Phosphate, on the other hand, is negatively charged because the (confusing) covalent bonding process between the oxygen atoms and the phosphorus atom leads to having two extra electrons floating about.
So when calcium is just floating around, phosphate comes by and shares its two extra electrons with calcium, thus making the molecule stable.
The new calcium phosphate salt now does not react in the way calcium (or any metal, really) reacts, nor does it react like phosphate.
Thus, calcium phosphate is not considered a metal. Calcium on its own is metal, but when bonded to something it no longer acts like a metal, so your bones are not considered "metal."
Bones are not made of "solid calcium" as you claimed, because the calcium is bonded to phosphates and hydroxides and is thus not "solid calcium" but "solid hydroxyapatite," which is constituted primarily of calcium bonded to other molecules.
Blood is red. Do you know why? Because of the iron. However, iron is silvery. I wonder how it's red then? It's because the iron in your blood is bonded to oxygen. You do not have pure iron in your blood, but rather iron oxide, which produces the red color.
Although, admittedly, just disregarding modern physics and saying we're made of metal IS in fact quite dwarfy.