The hepatic breakdown of citric acid ultimately produces water, carbon dioxide, and energy. Citric acid will participate in the process of tricarboxylic acid cycle in human liver, part of the citric acid is ingested through the digestive tract, part of the citric acid is formed by the condensation of acetyl CoA and oxaloacetate, and the decomposition reaction occurs through the catalysis of a variety of enzymes in the liver, and some of the energy will be released during the decomposition process. Citric acid undergoes decarboxylative degradation in the liver, first forming oxaloacetic acid, and then finally decomposing into water and carbon dioxide under the action of catalytic enzymes. Carbon dioxide is generally eliminated with the blood flow through the lungs by air exchange, and part of the water can be absorbed and utilized by the body, and part of it will be eliminated with the urine and sweat, and the energy is generally consumed in the cellular activities of the hepatocytes.