An organic sodium salt resulting from the replacement of the proton from the carboxy group of 3-hydroxybutyric acid by a sodium ion. ChEBI: Sodium 3-hydroxybutyrate is an organic sodium salt resulting from the replacement of the proton from the carboxy group of 3-hydroxybutyric acid by a sodium ion. It has a role as a human metabolite. It contains a 3-hydroxybutyrate.