Ca3C6H5O72

Ca3C6H5O72 is the shorthand formula commonly representing calcium citrate, the calcium salt of citric acid, with the systematic formula Ca3(C6H5O7)2. It is widely used as a calcium supplement and as a food additive to increase calcium content. In nutritional products, it is sold as calcium citrate tablets, capsules, or powders and is also added to fortified foods and beverages. Compared with calcium carbonate, calcium citrate is more soluble in water and its absorption is less dependent on stomach acidity, making it a practical option for individuals with reduced gastric acidity or those taking acid-suppressing medications.

Chemistry and production: Calcium citrate consists of three calcium ions coordinated to two citrate units. The solid dissociates in water to calcium ions and citrate ions. It is typically produced by neutralizing citric acid with a calcium salt such as calcium carbonate or calcium hydroxide, followed by crystallization and drying.

Uses and health aspects: As a calcium source, calcium citrate supports bone and dental health and helps prevent calcium deficiency. Its bioavailability is relatively high, and it can be taken with or without meals. Adverse effects are generally mild, though high doses may cause gastrointestinal upset. Excessive calcium intake may contribute to kidney stone risk in susceptible individuals and can interact with certain medications, including tetracycline antibiotics and iron supplements; dosing should follow product guidelines or medical advice.

Regulation: Calcium citrate is widely accepted as a dietary supplement ingredient and as an approved additive in many regions, with labeling indicating the calcium content per serving.

See also: Calcium carbonate, calcium citrate malate, dietary calcium supplements.