I have had 3 DEXA bone scans and 2 REMS Echolight scans over a 5 year period. DEXAS are covered by our medical plan, but I have to pay for private Echolight scans. My blood lab tests are mostly ordered by my PCP covered by our medical plan. If my PCP won't order them, the naturopath physician does this in which case I have to pay the lab but have some limited private benefit coverage. My PCP wouldn't order the CTX or vitamin D. The CTX is vital to know my rate of bone turnover and later to see if my interventions -- HRT, supplements, diet, exercise etc. -- are working to lower the bone turnover rate. My understanding is that the CTX can come down before the bone density score improves on the DEXA, which shows the interventions are working and success in stopping further bone loss progression if bone turnover is low enough.