>4.5mg/dL
Symptoms usually related to associated renal failure, hypocalcemia or hypomagnesemia
Metabolic Panel (with calcium, Magnesium, and Phosphorus)
Hyperphosphatemia
Calciphylaxis
Hypophosphatemia
Vitamin D intoxication
Hypocalcemia
Tumor lysis syndrome
Hypokalemia
Laxative 