Calcium lactate is a black or white crystalline salt made by the action of lactic acid on calcium carbonate. It is used in foods (as an ingredient in baking powder) and given medicinally. Its E number is E327. It is created by the reaction of lactic acid with calcium carbonate or calcium hydroxide.
Cheese crystals usually consist of calcium lactate, especially those found on the outside, on younger cheese, and on Cheddar cheese.
In medicine, calcium lactate is most commonly used as an antacid and also to treat calcium deficiencies. Calcium lactate can be absorbed at various pHs and does not need to be taken with food for absorption for these reasons.
Calcium lactate is added to sugar-free foods to prevent tooth decay. When added to chewing gum containing xylitol, it increases the remineralization of tooth enamel. It is also added to fresh-cut fruits, such as cantaloupes, to keep them firm and extend their shelf life, without the bitter taste caused by calcium chloride, which can also be used for this purpose.
It is also found in some over the counter mouth washes.