Calcium from Latin calx, meaning “lime” is the fifth-most-abundant element by mass in the Earth’s crust, and is also #5 for the most dissolved ion in seawater by mass. It is a major component in so much that is in our everyday world. Lime (essentially calcium) as building material was used since ancient times going as far back as 7000 to 14000 BC. Calcium is used in the extraction of other metals as a reducing agent, such as uranium, zirconium, and thorium and as a desulfurizer, deoxidizer, or decarbonizer for some ferrous and nonferrous alloys; also used in the production of aluminium, beryllium, copper, lead, and magnesium alloys as an alloying agent; for construction in the making of cements and mortars; to make cheese, in bringing about the coagulation of milk, where calcium ions influence the activity of rennin.
Interestingly, as present as calcium is all around you (it’s literally in the drywall walls in front of you) it is also an integral component of YOU – specifically your bones and teeth. The lion’s share (99%) of your calcium is in your skeleton and teeth. However, the remaining 1% is far from trivial. It is essential for important uses, such as neurotransmitter release, and muscle contraction.
It’s bones and teeth that command all the calcium attention, especially the growing problem of osteoporosis, which has hit epidemic proportions in Western countries. Osteoporosis is the condition where your bones have become porous to the point that fracture risk becomes very severe. What’s noteworthy and called the “Calcium Paradox” is that Western countries that statistically consume the most calcium, also suffer from the highest rates of osteoporosis.
It’s believed it’s a result of the calcium that we get largely from animal sources like milk, which is highly acidic to your blood. So though milk does provide ample calcium, it does not remain in the bones, but is instead pulled away in order to mop up, or ‘buffer’ the overly acidic blood. The net result is a calcium deficit, and increasing osteoporosis rates.