Normal Reference Ranges
Adult
100 - 300 (diet-dependent) mg/day
Pediatric
Varies by weight mg/day
Clinical Significance
Important for evaluating nephrolithiasis risk and staging hypercalcemia (specifically distinguishing primary hyperparathyroidism from FHH).
Causes of High
- Hyperparathyroidism
- Sarcoidosis
- Loop diuretics
- Excessive Vitamin D
- Bone metastases
Causes of Low
- Familial Hypocalciuric Hypercalcemia (FHH)
- Hypoparathyroidism
- Vitamin D deficiency
- Thiazide diuretics