Calcium homeostasis in the body is maintained through the balanced processes of bone resorption and deposition. Bone resorption occurs when calcium levels are low and is stimulated by PTH, while deposition occurs when calcium is high and is stimulated by calcitonin. Vitamins D, A, and C, as well as hormones like PTH, calcitonin, growth hormone, and sex hormones, regulate these processes and bone growth. Fractures heal through the stages of hematoma formation, deposition of temporary and bony calli, and bone remodeling. Osteopenia and osteoporosis can develop if bone resorption exceeds deposition over time due to factors like menopause and lack of exercise and calcium/