Changes in Bone Density: Decreased
Several terms are commonly used to describe the decreased density of bones. Osteoporosis is a disease of reduced bone mineral density that leads to fracture and is defined as measured by dual energy X-ray absorptiometry or quantitative CT. Osteomalacia describes bone softening due to defective bone mineralization. In children, osteomalacia is known as rickets, and because of this the term osteomalacia is often restricted to the adult form of the disease. Although many of the features of osteoporosis and osteomalacia overlap, they are distinct disorders.
Osteomalacia is a defect in mineralization of osteoid, the protein framework in bones, and is usually the result of low vitamin D levels. Osteopenia is a term for low bone mineral density and may be a precursor to osteoporosis.