PTH and Hypocalcemia: One explanation for this discrepancy may be that despite a detectable PTH by the assay, the amount of PTH available in the serum to maintain normocalcemia remained low.[23] Furthermore, there might have been other factors, including parathyroid autotransplantation, that could influence the risk of hypocalcemia; in addition, PTH-SC was not a test with 100 % accuracy.