The likely causes of the abnormality, the physiological responses to the abnormality and how the defect could be treated a patient presents with no detectable 1, 25 dihydroxy vitamin D3 despite the fact that his 25-hydroxy vitamin D3 is at normal or eleva

1-alpha hydrox defic. Are you in medical school? The lab profile you describe is seen in 1-alpha hydroxylase deficiency. Treatment for this is Calcitriol at physiologic doses.
Calcidiol. Calcidiol is a substance that is converted in the kidneys to form calcitriol, or 1/25 dihydroxycholecalciferol (1, 25 oh2d). This is a ligand of the vitamin d receptor. This process is partially mediated by the parathyroid hormone. So, it would be important to know if this patient has an abnormal parthyroid, and if they had low calcium or phosphate levels. It sounds like this patient has a very complicated picture and hopefully is being cared for by an endicronologist.