Density can be defined as quantity per unit of space or mass per volume, so bone mineral density refers to the amount of minerals in a specific area of the bones, which gives an overall picture of bone health. Bone mineral density decreases as people age, particularly for women, which can cause health problems later in life.
Bone Composition
Calcium compounds are the most prevalent minerals in bones, with phosphorus second. Magnesium and sodium also are present. Along with living cells, minerals are deposited and stored in the bones to give them hardness and strength. People need proper nutrition, especially calcium and vitamin D, to maintain bone health. Rickets, for instance, is a disorder involving softening of the bones in children when their bones are forming because they are not obtaining enough vitamin D.
Bone Density Problems
In all people, existing bone is dissolved and absorbed into the bloodstream, while new bone develops. After age 30, people's bones start becoming thinner, a condition called osteopenia, caused by existing bone deteriorating faster than new bone is created. This causes bones to lose minerals and become less dense. When a certain level of density is lost, osteopenia has progressed to osteoporosis, where the bones are weak enough to significantly increase the chance of fracture. Both women and men are more apt to have osteopenia if they fail to reach their optimal bone mineral density by age 30.
Gender Differences
Bone loss is more common in women than men. Women are advised by the American College of Obstetricians and Gynecologists (ACOG) and the National Osteoporosis Foundation (NOF) to have a bone mineral density test of the hip and spine by age 65. Women might consider having a baseline test when they begin menopause, especially those with particular risk factors such as a family history of osteoporosis and being a smoker. Much of a woman's bone loss occurs in the first five to seven years after menopause, as noted by physician Judith Reichman, a medical contributor to NBC's TODAY show. This is especially true for women not taking estrogen therapy. Additionally, young women with an estrogen deficiency are at increased risk for lower bone mineral density. Women who are pregnant or breastfeeding also experience bone mineral density loss, although it is easily regained with proper nutrition.
Bone Mineral Density Test
A bone mineral density test is the only way to determine problems with density. It compares the person's results with the optimal peak bone density for a healthy young adult of that sex. Tests are safe and painless, with no needles or other invasive instruments. Typically the test is performed with a central dual energy X-ray absorptiometry (DXA) machine. It also may be done with computed tomography or ultrasound.
Prevention/Solution
People can increase bone density and bone strength by taking calcium and vitamin D supplements, walking for exercise and doing weight training. Prescription drugs also are available to help avoid bone mineral density loss.
Tags: mineral density, bone mineral, bone mineral density, bone density, bone health
