Osteomalacia Osteomalacia is the bone disease that results from impaired mineralisation of newly formed bone. The result is excess unmineralised bone matrix (known as osteoid tissue). Osteomalacia is due to a lack of vitamin D, impairment of vitamin D metabolism, or to a lack of calcium or phosphorus at the mineralising site. Before puberty the same condition is referred to as rickets and is characterised by failure of calcification of cartilage at the growth plate (that is, decreased endochondral ossification). See later: • Clinical Features of Osteomalacia • Diagnosis of Osteomalacia • Calcium Homeostasis in Osteomalacia • Hypophosphataemic Rickets • Oncogenic Osteomalacia • Treatment of Osteomalacia