Alpha-ketoglutarate, malate, and citrate summary

Alpha-Ketoglutarate, malate, and citrate are organic acids that serve as intermediates in the citric acid cycle.

The citric acid cycle, also known as the tricarboxylic acid (TCA) cycle or the Krebs cycle, is a series of chemical reactions used to release stored energy through the oxidation of carbohydrates, fats, and proteins into carbon dioxide and chemical energy in the form of NADH and ATP. This cycle is fundamental to all aerobic (oxygen-requiring) life, including humans.

Alpha-ketoglutarate, Malate, and Citrate can be synthesized in the body by the citric acid cycle, and are not required in the diet. Deficiency is unknown.

The role of citric acid intermediates in the treatment of ASD has not been studied. Several lines of evidence support the notion that some children with ASD have abnormal mitochondrial metabolism (this topic is reviewed in https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4910649/pdf/cmped-10-2016-043.pdf).

Alpha-ketoglutarate is sometimes used to boost athletic performance and to help heal wounds. In addition, alpha-Ketoglutarate can reduce levels of ammonia (and excess nitrogen) formed in the brain, muscles and kidneys. Malate and citrate are all frequently provided as part of mineral supplements. Citrate is sometimes used to prevent kidney stones and to alkalize the blood or urine in various conditions.

Side effects are rare at usual doses used in supplementation.

Urine organic acid testing can quantify these citric acid intermediates, but this is not likely to be of clinical utility other than in screening for metabolic/mitochondrial disorders.