beetahydroksibutyraatin

Beetahydroksibutyraatin, known in English as beta-hydroxybutyrate (BHB), is a ketone body that circulates in the blood and serves as an alternative energy substrate when carbohydrate availability is limited. It exists mainly as the D-enantiomer in human metabolism, with the L-enantiomer present in smaller amounts.

Biochemically, BHB is produced in the liver during ketogenesis from acetyl-CoA, a process activated by fasting, prolonged exercise, or ketogenic diets. It is released into the bloodstream and can be converted back to acetyl-CoA in peripheral tissues, providing energy through the citric acid cycle. This interconversion involves enzymes that use NAD+/NADH as cofactors, reflecting the redox state of the cell.

Physiological role and distribution: BHB is an important energy source for many organs, including the heart and brain, especially during periods of low glucose. It crosses the blood-brain barrier via monocarboxylate transporters and can help spare glucose utilization in the brain and other tissues during starvation.

Clinical and dietary relevance: Exogenous BHB is available as ketone salts or esters and is used to raise blood ketone levels for various purposes, including experimental therapies, ketogenic-diet strategies, and some athletic or cognitive applications. Evidence for therapeutic benefits is mixed and context-dependent, with stronger support for epileptic seizure reduction in some cases and ongoing investigation for neurodegenerative diseases.

Safety and monitoring: Elevated BHB levels occur in physiological ketosis but can indicate ketoacidosis in diabetic or other metabolic disorders when uncontrolled. Supplements can cause gastrointestinal discomfort and electrolyte shifts; use should follow medical guidance, especially in preexisting medical conditions.