This 2021 study explores how declining NAD⁺ levels in osteoblast progenitor cells contribute to age-related bone loss. Researchers found that aged mice exhibited reduced NAD⁺ levels in osteoprogenitors, leading to increased acetylation of FoxO1 and β-catenin, markers of cellular senescence, and diminished osteoblastogenesis. Supplementation with the NAD⁺ precursor nicotinamide riboside
