Increased in:

• Primary hyperparathyroidism
• Secondary hyperparathyroidism due to renal disease
• Pseudohypoparathyroidism, Types I and II
• Pseudo-idiopathic Hypoparathyroidism
• Rickets
• Osteomalacia
• Vitamin D deficiency
• Some drugs: Anticonvulsants, furosemide, propofol, phosphates

Decreased in:

• Hypercalcemic states other than primary hyperparathyroidism
• Hypoparathyroidism
• Parathyroidectomy
• Thyroid Surgery, some
• Autoimmune Hypoparathyroidism
• Sarcoidosis
• Hyperthyroidism
• Hypomagnesemia
• Malignancy with hypercalcemia
• Nonparathyroid hypercalcemia