Dr. Rinku Mehra and Dr. Lindsey Waldman discuss pediatric bone health, explaining that bones are metabolically active and shaped by osteoblasts, osteoclasts, and osteocytes, with growth plates driving length until estrogen closes them in puberty. They emphasize peak bone mass, noting 40–60% is built in adolescence and ~90% by late adolescence/early adulthood. Practical guidance includes age-based calcium needs (1–3: 700 mg/day; 4–8: 1,000 mg/day; 9–18: 1,300 mg/day) spread throughout the day, calcium-rich foods (milk, yogurt, cheese, fortified plant milks, calcium-set tofu, leafy greens), and vitamin D (~600 IU/day) from sunlight, fortified foods, fatty fish, or supplements. They highlight weight-bearing/high-impact activity for bone density, key hormones (GH/IGF-1, estrogen, testosterone), risk factors (celiac, IBD, arthritis, kidney disease, lo ...