I am 35 yr old female. Recently I just received a slightly elevated calcium result at 10.3 mg/dl. I opted to retest 2 days later, the level dropped to 9.6. Could the higher test be a fluke? The day of the test, I did not drink much water and the test was late in the afternoon. My retake was first thing in the morning with plenty of water. My previous levels are listed below: Oct 2022-9.5 Apr 2023- 9.0 Nov 2023-9.2 Feb 2024- 9.9 Mar 2024 - 10.3 Mar (2 days later) 2024- 9.6 Thanks so much for your input.
Single instances of elevated calcium can be flukes, but they can also indicate early parathyroid disease. It is certainly possible that your calcium of 10.3 was a fluke. Whenever I get a lab result that is surprising and different from prior results, I always like to repeat it to make sure it is accurate. If all prior and subsequent results were normal, with just one weird result in the middle, then we can often conclude that the weird result was incorrect.
Having said that, I would not ignore it just yet. With primary hyperparathyroidism, we see fluctuations in calcium, particularly in early disease. Sometimes we can recheck over a couple of weeks and see the calcium level go from normal to high and then back again. Over time, the calcium level will tend to be in the high range more often, until eventually it stays in the high range. That process can take a few years though. In cases in which we can’t quite make a diagnosis, I recommend following the calcium levels over time, since eventually it will become clearer.
In your case, you are still young, and having calcium levels in the low 10s is not unusual. People in their 30s can have calcium levels in the low 10s, which eventually start to trend down into the 9s as you get to 40 and older. For a 60-year-old, a calcium of 10.3 mg/dl is high. For a 35-year-old, it is borderline, but I would not yet label it high. It is a change from your prior results, though, and in general the calcium will go down as you move through your 30s, not up.
I would recommend watching your calcium and making sure that it stays in the 9s. If you have more calcium levels in the 10s, then I recommend checking calcium, PTH, and Vitamin D levels together.
