Calcium Alpha-Ketoglutarate

Calcium alpha-ketoglutarate is the calcium salt of alpha-ketoglutarate (AKG), also called 2-oxoglutarate, a small molecule that the body makes as an intermediate of the citric acid cycle, the central pathway of cellular energy production ^[1][2]. In this salt form the acid is paired with calcium, giving a stable, water-soluble white powder that is convenient to store and take by mouth, and it is the version of AKG used in most recent aging research ^[1][4]. Alpha-ketoglutarate itself is not a vitamin or a foreign drug but an ordinary metabolite whose levels naturally shift with fasting, exercise, and age ^[1].

Inside cells, alpha-ketoglutarate serves several roles beyond fueling the Krebs cycle. It sits at a hub of nitrogen and amino acid metabolism, acting as a carbon skeleton that can be converted to and from glutamate and glutamine and thereby helping balance ammonia ^[2]. It is also an essential co-substrate for a large family of enzymes known as 2-oxoglutarate-dependent dioxygenases, which include the prolyl hydroxylases involved in collagen formation and oxygen sensing and the TET and JmjC enzymes that remove methyl marks from DNA and histones; through the latter, AKG influences the epigenetic control of gene activity ^[2]. Some studies additionally describe antioxidant behavior, with AKG scavenging reactive oxygen species ^[2].

Much of the modern attention to Ca-AKG comes from work on aging. In a study in mice, alpha-ketoglutarate delivered as its calcium salt extended lifespan and, notably, compressed the span of late-life illness, an effect the authors linked to lower levels of inflammatory signaling molecules and increased production of the anti-inflammatory cytokine IL-10 ^[1]. Reviews note that earlier human studies from the 1980s and 1990s had reported benefits for muscle, wound healing, and surgical recovery, and that AKG extends life in worms and mice, but they caution that rigorous trials in people are still lacking ^[2]. A retrospective analysis of individuals taking an AKG-and-vitamin formulation reported a reduction in biological age as estimated by a DNA-methylation clock, though it had no control group ^[3], and a randomized, placebo-controlled trial of sustained-release Ca-AKG was designed to test the biological-age question more carefully in middle-aged adults ^[4]. Laboratory work has also explored possible neuroprotective effects, for example on synaptic function in a mouse model of Alzheimer's disease ^[5].

Calcium alpha-ketoglutarate is sold as a dietary supplement rather than an approved medicine, frequently in capsule or sustained-release form, and sometimes combined with vitamins ^[3][4]. Despite enthusiastic marketing, reviewers emphasize that the human evidence remains preliminary and that the compound's effects on aging and age-related disease have yet to be confirmed in large controlled trials ^[2].

Appears well tolerated in the limited human use so far. The calcium content means very high doses add to your calcium intake, which matters for people watching cardiovascular or kidney risk. Mild GI effects are possible. Long-term safety in humans isn't established.