Calcium citrate, a naturally occurring chemical in most plants and animals, is the calcium salt derived from citric acid. Calcium citrate is present in foods which have naturally occurring citric acid. Calcium citrate is used as a calcium supplement and 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). Calcium citrate may be chemopreventive for colon and other cancers. Calcium citrate is used as an ingredient in dietary supplements, and as a nutrient, sequestrant, buffer, antioxidant, firming agent, acidity regulator (in jams and jellies, soft drinks and wines), as a raising agent and an emulsifying salt. It is also used to improve the baking properties of flours and as a stabilizer.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. Calcium citrate is also used as a water softener because the citrate ions can chelate unwanted metal ions. Calcium citrate is also found in some dietary calcium supplements (e.g. Citracal). Calcium makes up 21% of calcium citrate by weight. In food industry, it is used as anti-caking agent ,nutritional supplement (fortified calcium), pH regulator and buffering agent. It's also used in flour, powder milk, candy, pudding and so on.