Major causes of hypocalcemia, according to phosphate level
| Serum parathyroid hormone level | |
|---|---|
| High serum phosphate | |
| End-stage renal diseasea (estimated glomerular filtration rate < 15 mL/min) | High |
| Acute phosphate load | High |
| Endogenous source (rhabdomyolysis, tumor lysis syndrome) | |
| Exogenous source (eg, phosphate enemas) | |
| Primary hypoparathyroidism | Low |
| Pseudohypoparathyroidism | High |
| Low or normal serum phosphate | |
| Vitamin D deficiency | High |
| Vitamin D resistance | High |
| Hypomagnesemia | Low |
| Drugs (eg, bisphosphonates, denosumab, calcitonin, plicamycin, foscarnet, fluoride, intravenous contrast) | High |
| Acute pancreatitis | High |
| Sepsis | High |
| Massive blood transfusion, plasma exchange, leukapheresis | High |
| Acute respiratory alkalosis | High |
| Osteoblastic bone metastasis (breast, prostate cancer) | High |
↵a A high parathyroid hormone level in end-stage renal disease is due to secondary hyperparathyroidism.