Active and inactive Vitamin D supplements

I went to meet an Endocrinologist, Dr. Rakesh Sahay, on the advice of my nephrologist, Dr. Girish Narayen on Saturday. After listening to everything and looking at my reports, Dr. Sahay suggested that I take Rocaltrol 0.25 mcg twice a day (this is the active form of Vitamin D3) and Calcirol granules (the inactive form) once a week.

I asked him about the possible hypercalcemia that is a side effect of rocaltrol. I also wondered about the PTH that Vit D supplements suppress. My PTH was already low. He said I should try this for a week and then check my Calcium, Phosphorus and PTH and then we could decide the further course of action.

I called Dr. Girish Narayen and told him this. He was also concerned about the hypercalcemia and the PTH. He had a chat with Dr. Sahay and they agreed to try it for a week and then take a call. I was also asked to use a low Calcium acid solution to try and prevent the Calcium from going too high.

I really don't get it, though. The purpose of Vitamin D in relation to the bones is to improve Calcium absorption from the gut. If I am being asked to reduce Calcium in my dialysate, what purpose is it going to serve to increase the Vit D?

I am trying it anyway (what choice do I have?). It is frustrating to have an undiagnosed problem and suffer continuously not knowing where you are heading. At least if I had a firm diagnosis and was getting some treatment, I would have the consolation that there is a clear end in sight. Currently I have no clue what the problem is and what I could do to help it.