Calcium lactate is a black or white crystalline salt made by the action of lactic acid on calcium carbonate. It is used in foods and given medicinally.nCalcium is a mineral that is found naturally in foods. Calcium is necessary for many normal functions of your body, especially bone formation and maintenance. Calcium can also bind to other minerals (such as phosphate) and aid in their removal from the body.nCalcium is necessary for many normal functions of your body, especially bone formation and maintenance. Calcium can also bind to other minerals (such as phosphate) and aid in their removal from the body. Calcium lactate is used to prevent and to treat calcium deficienciesn It may be used to treat conditions caused by low calcium levels such as bone loss (osteoporosis), weak bones ( osteomalacia /rickets), decreased activity of the parathyroid gland (hypoparathyroidism), and a certain muscle disease (latent tetany). It may also be used in certain patients to make sure they are getting enough calcium .