Question: I recently had my annual lab work done and most of it was normal. There was one test which was calcium that came back at 10.3. The normal range is 8.6-10.3 and the lab was Quest diagnostics. My doctor called with all my results and made no mention of calcium being on high end of normal. I questioned it after seeing him after this and he decided to order a PTH intact with ionized calcium. Got these results and the ionized calcium was 5.7, reference range 4.8-5.6, PTH intact was 10, reference range 14-64 and calcium was checked and it was 10.3, reference range 8.6-10.3. This test was done by Quest Diagnostics. My doctor ordered a vitamin D test and it was 31 which is normal. I am a 57 year old male and from what I have read it seems that my calcium is too high and now that the ionized is slightly higher than normal I am concerned that there is a major issue going on like cancer. Usually my calcium levels are around 9.8, once in 2017 it was 10 but otherwise it typically is in the nines. I have also read that this could be hypercalcemia of malignancy. Lot of confusing information on the internet. My doctor said if it was cancer that calcium would likely be much higher, closer to 13 or more. He doesn't seem very concerned so I am thinking I should get another cmp test and have the calcium checked since it has been 2 weeks since the ionized calcium and total calcium was checked. What is your opinion on the information I provided? I also read that ionized calcium tests can be skewed if the blood isn't drawn properly and also if the sample isn't tested within hours of collection. There were some issues when the blood was drawn because the techs couldn't find veins and there was a lot of fist clenching.

Thanks for the response. Here are some of the results of the blood tests you suggested which weren't included in the original question. UREA NITROGEN (BUN) 34, reference range 7-25, Creatinine 1.10, reference range 0.70-1.33, Bun/creatinine ratio 31, reference range 6-22 (calc), TSH 0.92, reference range 0.40-4.50 mIU/L, T4 Free 1.2, reference range 0.8-1.8 ng/dL

As you can see the urea/bun and bun/creatinine are higher than normal. My bun is always higher than normal although these results were slightly higher than previous lab tests.

The fact that my ionized calcium is slightly elevated and PTH is so low doesn't raise concerns? Also is it true that being and adult that your calcium should really be in the nines and not above 10?

Is it possible that the urea/bun and bun/creatinine being higher than normal are causing the ionized calcium to be above normal?

Based on all the information I provided is this considered hypercalcemia?

Do I need to do any other blood tests at this point and do you think I should recheck my serum calcium?

Thanks