Will a vitamin D test tell me if I need more vitamin D?
That depends on whom you ask. As part of your regular blood test, your doctor can order a test for 25-hydroxyvitamin D (25-OHD).
The problem is not with the test. The problem is how to interpret the results. An expert committee convened by the Institute of Medicine in November 2010 concluded that "the cut-point values used to define deficiency, or as some have suggested, 'insufficiency,' have not been established systematically using data...
Osteoporosismedications and physical activity can tip the balance of bone remodeling, preserving bone strength. How does bone remodeling work? What can be done to slow down or reverse bone loss? Read on to learn what you can do to keep your bones healthy and strong.
Bone Remodeling: A Never-Ending Improvement Project
"People think bones are static, but in fact bone is constantly growing and being resorbed," says Mary Zoe Baker, MD, an endocrinologist and professor of medicine at the University of Oklahoma Health Sciences Center in Oklahoma City. "It has to, in order to heal damage and microfractures" that occur with normal wear and tear, says Baker.
The process of bone remodeling is a give-and-take between two opposing forces, replacing old bone with new bone.
Bone loss (resorption): Special cells called osteoclasts break down bone. They are like a demolition crew. When the signal comes, osteoclasts are recruited to enter the bones and secrete enzymes that break down collagen and minerals. Somehow, they know just when to stop to avoid damaging the bone.
Bone growth:Special cells called osteoblasts line the surface of bones. In response to signals in the blood, the osteoblasts get to work. They lay down bone, by depositing calcium and phosphate crystals on a scaffolding of collagen.
In healthy bone, the processes of growth and resorption are equalized. Various hormones, including estrogen in women, help keep this balance.