When people donate blood, they also donate the excess iron in that blood.
Having too much iron shortens your life. This is the main reason why women generally live 4 to 7 years longer than men... simply because they menstrate, thus eliminating excess iron.
High blood pressure, osteoperosis, loose teeth, receding gums, foot cramps, and eye twitches are all caused by being deficient in calcium.
Since magnesium regulates calcium, it is also an important nutrient, as are all 60 vitamins/minerals. Calcium can't be absorbed without vitamin D... just another example of how these nutrients work synergistically.
There are about 90 essential vitamins, minerals, amino acids, and fatty acids, and being deficient in one of these can cause up to 10 diseases. Therefore, these 90 can protect against 900 diseases, which is a pretty good reason not to be deficient...
And you can take all the vitamins you want, but they will not work without the mineral co-factors, that's just how it is.
Let Food Be Your Medicine And Medicine Be Your Food.(Hippocrates)