Vitamin K2 ameliorates pregnancy- and lactation-associated osteopenia and postpartum depression.

Vitamin K2 (VitK2) supplementation ameliorates comorbid pregnancy- and lactation-associated osteopenia (PLO) and postpartum depression (PPD). These improvements are accompanied by reduced relative abundance of Bacteroides uniformis (B. uniformis) and lower serum deoxycholic acid (DCA) levels. DCA inhibits osteoblast differentiation, promotes osteoclast differentiation, and contributes to an imbalance between hippocampal glutamatergic and GABAergic signaling. Maternal VitK2 supplementation also improves offspring cognition. These findings suggest that modulation of the gut microbiota-bile acid axis may contribute to the beneficial effects of VitK2, supporting the potential of VitK2 as a therapeutic agent for PLO and PPD.