Hi drsuefowler, when I got my first Dexa and it surprisingly showed osteoporosis, my doctor did a bunch of lab tests and one of them was the 24-hour urine test. The calcium level in my urine came back very high. Then they did more tests to check PTH and I can't remember what else, and, because all the tests were normal (blood calcium level always normal), determined that there was no known reason why this was happening.