Maintaining bone health involves complex interactions among nutrients, hormones, and physiological mechanisms, with vitamin D playing a pivotal role. Vitamin D is essential for the absorption of calcium and phosphate, which are critical minerals for bone development, maintenance, and repair. Disruptions in mineral ion homeostasis can lead to conditions such as hypocalcemia, osteoporosis, osteomalacia, and rickets, which are prevalent worldwide. Inadequate vitamin D impairs bone health, increasing the risk of fractures and catabolic bone diseases. This chapter elaborates on the synthesis, activation, and function of vitamin D, highlighting its essential role in bone health, from supporting growth in children to maintaining bone strength in adults. It also elaborates on how vitamin D enhances healing after a fracture by regulating the immune response, inflammation, and mineralization process.