evidence: VitD also influences cellular signaling involved in myogenesis and activates adenosine monophosphate-activated protein kinase (AMPK) during metabolic stress. [...] VitD also plays a crucial role in regulating immune responses by its widespread distribution among immune cells and autonomic control of active VitD concentration at inflamed sites. [...] Studies indicate VitD's role in enhancing antimicrobial peptides, stabilizing gut barriers, and regulating microbiota composition.