All men and many women with osteoporosis need to be evaluated to find the cause. More than 75 percent of men with osteoporosis have a serious cause (Osteoporosis International, published online October 9, 2010). Common causes include *low levels of the male hormone, testosterone, *vitamin D deficiency, *excessive loss of calcium through the urine, *an overactive thyroid, *being given too much thyroid hormone, *an overactive parathyroid gland, *smoking, *drinking too much alcohol, *not getting enough exercise, or *taking certain drugs, such as cortisones, that weaken bones.
All people with weak bones should get the following tests: 25-hydroxyvitamin D, testosterone, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, parathyroid hormone, and spot urinary calcium-to-creatinine ratio, calcium, phosphorus, and creatinine. If that doesn't tell you why your bones are weakened, you may need to be checked for inability to absorb calcium from your intestines (celiac panel), bone disease (such as multiple myeloma), or taking glucocorticoids, which are often prescribed to transplant patients and those with autoimmune diseases.