If you suffer from severe back pain and your doctor has not found a cause, ask him or her if you need a bone density test to determine if you have osteoporosis.
All women and most men will suffer osteoporosis if they live long enough. Your bones are strongest in your twenties and become progressively weaker after that. Back pain can be caused by arthritis, pinched nerves and structural defects, but it also can be the only sign of osteoporosis, so most older people with back pain should get a bone density test.
Taking extra calcium and vitamin D does not cure osteoporosis. If your bone density test suggests that you have osteoporosis, discuss your treatment options with your doctor. Various medications can be used to increase bone density, but no one has shown that bone density is equivalent to bone strength, and the available medications can have serious side effects. So far, the only way we have to strengthen bones without risking side effects is to lift weights against resistance. See Preventing Osteoporosis