I had my thyroid out 5 years ago. My parathyroid glands were damaged in the surgery. I currently take 600 mg calcium carbonate 3x daily, along with Rocaltrol 0.25 ug twice daily. My endocrinologist told me to switch to calcium citrate as I am still not achieving the proper calcium levels. My problem has been finding calcium citrate without added Vitamin D, as I do not want to overdose on Vitamin D. I have just found a source for Calcium CItrate wihout added D, but it s 1,000 mg....what would be the equivalent to the current calcium carbonate 1800 daily I am taking? My endocrinologist suggested that the calcium citrate would be smaller doses, but he has gone on vacation for 6 days, and I was hoping to start the new regimen before that...