The skeleton is the framework of bones that supports the body, protects vital organs, and anchors the muscles that move us. An adult carries 206 bones, living tissue constantly remodelled by the opposing actions of osteoblasts that build and osteoclasts that resorb. Nutrition builds and maintains it: calcium and phosphorus mineralise the matrix, vitamin D enables calcium absorption, protein provides the collagen scaffold, and vitamin K, magnesium, and trace minerals all play parts. Peak bone mass is laid down by early adulthood, then slowly drawn down, which is why childhood and adolescent nutrition casts such a long shadow over osteoporosis risk decades later. The skeleton is also a mineral bank, releasing calcium to the blood when diet falls short.