DefinitionOsteoporosis is the thinning of bone tissue and loss of bone density over time.Alternative NamesThin bonesCauses, incidence, and risk factorsOsteoporosis is the most common type of bone disease.Researchers estimate that about 1 out of 5 American women over the age of 50 have osteoporosis. About half of all women over the age of 50 will have a fracture of the hip, wrist, or vertebra (bones of the spine).Osteoporosis occurs when the body fails to form enough new bone, when too much old bone is reabsorbed by the body, or both.Calcium and phosphate are two minerals that are essential for normal bone formation. Throughout youth, your body uses these minerals to produce bones. If you do not get enough calcium, or if your body does not absorb enough calcium from the diet, bone productio