We are concerned that I have primary hyperparathyroidism. My calcium levels have been moderately high since 2019. I also began having high blood pressure, vitamin D deficiency, and became diabetic around the same time. I am 52 and since July of this year, my calcium has been 10.9, 11.6, and 10.9 mg/dl. The last two readings were two days apart and my doctor ordered tests for ionized calcium (5.5, but at the highest point of normal) and PTH intact as well. PTH was 33 pg/ml. Vitamin D 25-OH is 32 ng/ml. Many things I read comment on high PTH levels or low, but this confuses me. I have taken my total exhaustion for the last few years as just the 5 kids, but I have literally almost no energy whatsoever and I started having migraines in July pretty regularly. Is my gut feeling that it requires surgery the right way to go? I ask, because my doctor never said anything about my calcium levels over the last few years and it has been 10.4 or higher since 2019. It was only after it hit 11 that she wanted me to take extra tests.
Thanks for writing. Based on your calcium levels, I am also concerned about primary hyperparathyroidism. High calcium levels are not normal, and the most common cause of persistently elevated calcium is primary hyperparathyroidism.
Your calcium has been elevated since at least 2019, based on what you have said. A calcium level of 10.4 mg/dl is not normal for adults over age 40. If your calcium levels were in the 9s prior to 2019, then the diagnosis of primary hyperparathyroidism is very likely.
To confirm the diagnosis, we check calcium and PTH levels together. PTH levels confuse a lot of people, including many physicians. Physicians sometimes believe that you need a high PTH level in order to diagnose primary hyperparathyroidism, but this is not the case. A high calcium, combined with a normal or high PTH, indicates primary hyperparathyroidism.
I encourage everyone to move away from thinking about PTH in terms of “low” or “high” and instead think of them as being “appropriate” or “inappropriate.” The lab may give a “normal range” for PTH, but PTH can never be interpreted alone. It can only be interpreted in relation to the calcium level, since the parathyroid glands exist solely to regulate calcium. If the serum calcium level is low, then parathyroid glands are designed to make more hormone (PTH) in order to raise the calcium back to normal range. If the calcium goes too high, the parathyroids are designed to stop making PTH in order to allow the calcium to drop. So, for example, it is entirely appropriate for the PTH to be “high” when the calcium is low. And if the calcium is high, the appropriate response will be a low PTH. If you have a high calcium, but the PTH is still within the “normal” range, then that is inappropriate, since the appropriate response is to stop making PTH.
Now let’s look at your levels: your calcium levels are clearly high. Your PTH of 33 pg/ml is on the lower end of “normal range,” but not in the low or suppressed range. This means that your labs are consistent with primary hyperparathyroidism.
Important caveat: While your labs can indicate primary hyperparathyroidism, PTH levels in the low-normal range are uncommon in the disease. It is much more common to have levels in the mid to high-normal range (i.e. 40 pg/ml or higher). When the PTH levels are all in the 20s or 30s, with high calcium levels, I will consider other diagnoses. The most common is overuse of Vitamin D. Vitamin D can raise calcium levels and cause the PTH to be in the low or low-normal range. Your Vitamin D level is in the lower end of normal, so this does not appear to be the cause of your high calcium.
The next step would be to repeat calcium and PTH levels. Often, the PTH level fluctuates, so it could be 33 one day and 70 the next. When the PTH is on the low end of normal, I always repeat it at least once or twice. Even if your PTH level stays in the 30s, you would still need parathyroid surgery if no other cause of high calcium is found. You can already rule out many other causes of high calcium, such as cancer, since that would give you a very low PTH (single digits typically).
Your labs already are most consistent with primary hyperparathyroidism, but I would repeat the calcium and PTH at least once. And then the treatment is surgery.
