Brief Answer: Parathyroid Detailed Answer: Your calcium seems to be in the normal range although individual labs have slight variations in their reference ranges for normal based on the assay kits they purchase for testing method. The parathyroid levels are clearly elevated. There are 4 possibilities here: 1 Lithium is known to cause elevations in parathyroid and calcium. It typically improves after discontinuation of lithium. However, it is important to determine if this is feasible or not and therefore the prescribing physician must make that call as to whether it is safe to withdraw the medication 2 Low vitamin D levels in the blood can raise parathyroid hormone levels as a compensatory response. Testing for, and treating the low levels(if deficiency found) often normalizes the parathyroid levels. 3 The total calcium levels can sometimes be misleading. The true and most accurate calcium test for blood levels is called 'Ionized Calcium'. It is important to know if the calcium is also high or not because the treatment approach changes. 4 There is an uncommon condition called FHH in which the PTH calcium rise modestly. It does not require any treatment. This condition is best diagnosed by an endocrinologist who usually will check magnesium levels in the blood along with a special type of urine calcium/creatinine testing.

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