Word Origin & History. critical 1580s, censorious, from critic + -al (1). Meaning pertaining to criticism is from 1741; medical sense is from c.1600; meaning of the nature of a crisis is from 1640s; that of crucial is from 1841.
Calcium citrate is the calcium salt of citric acid. It is commonly used as a food additive (E333), usually as a preservative, but sometimes for flavor.In this sense, it is similar to sodium citrate.alcium citrate is also found in some dietary calcium supplements (e.g. Citracal).
Caltrate Calcium Source. Caltrate contains calcium carbonate, a chemical found naturally in egg shells, snail and oyster shells, pearls, chalk, limestone and marble. Calcium carbonate is a relatively inexpensive and dense source of elemental calcium that contains 40 percent calcium by weight.