I was recently diagnosed with high blood calcium (10.8, three separate blood tests done), with normal PTH and very low vitamin D.  My doctor prescribed Vitamin D (50,000 per week).  Wont this just raise my calcium even more?  What could be causing high calcium with a normal PTH?  What should my next step be?
You may get the following tests done-Ionized calcium level(Ionized calcium level is a different test from the total calcium level that you have given here). You may also get as serum phosphorus, blood urea, serum creatinine, ESR test done. From the information provided your high calcium also called hyperkalemia is in the mild range. As your PTH is normal, a condition called hyperparathyroidism which can cause high calcium is ruled out. As your vitamin D is low it is essential to continue with your vitamin D as prescribed because low vitamin D affects your bones and several other metabolic processes. High calcium may occur non specifically if you are taking medicines called thirties which are prescribed for conditions such as high blood pressure etc. Some other causes of high calcium are hyperparathyroidism which is ruled out in your case because the PTH is ok. Rarely high calcium levels are seen in people with certain cancers of the lung, bones etc. You may get the tests done and post your detailed queries here for further information. Best regards