Parathyroid Q&A is a community of experts and patients dedicated to understanding and treating Parathyroid Disease.


I just received my test from my bloodwork and wanted to know if I should be worried about a calcium level that was 10.3 mg/dl?

Deva Boone
Answer authored by Deva Boone
Deva Boone, MD is the founder of the Southwest Parathyroid Center. As one of the most experienced parathyroid surgeons in the U.S., she has treated thousands of patients with parathyroid conditions.

If your blood calcium level is 10.3 mg/dl, it’s important to consider several factors before determining if there is cause for concern:

Age: Calcium levels tend to decrease slightly with age. If you are in your 20s or 30s, a calcium level of 10.3 mg/dl can be within the expected range. However, if you are 40 or older, it is less common to see levels above 10.0 mg/dl. Most of the time, persistent calcium levels above 10.0 in adults over about the age of 40 indicate primary hyperparathyroidism.

Other Labs: It’s crucial to check other labs before making a diagnosis. To interpret a calcium level, we need the PTH (parathyroid hormone) level, and Vitamin D is also helpful. A high calcium, paired with a high or “normal” PTH, indicates likely primary hyperparathyroidism. A very low PTH associated with a high calcium indicates that something other than parathyroid disease is the cause.

Supplements and Medications: High calcium levels can sometimes be influenced by supplements and medications. Are you taking Vitamin D supplements? High-dose Vitamin D can cause elevated calcium levels.

If I see a patient with a calcium of 10.3 mg/dl, the next step is repeating the labs and including a PTH and Vitamin D level with the calcium level.

Diagnosis Hypercalcemia