In medicine, hypocalcaemia is the presence of less than a total calcium of 2.2 mmol/L (9mg/dl), or an ionized calcium of less than 1.1 mmol/L (4.5 mg/dL) in the serum.

Causes

• absent parathyroid hormone (PTH)
  • hereditary hypoparathyroidism
  • acquired hypoparathyroidism
  • hypomagnesemia
• ineffective PTH
  • chronic renal failure
  • absent active vitamin D
    • decreased dietary intake
    • decreased sun exposure
    • defective Vitamin D metabolism
      • anticonvulsant therapy
      • vitamin-D dependent rickets, type I
  • ineffective active vitamin D
    • intestinal malabsorption
    • vitamin-D dependent rickets, type II
  • pseudohypoparathyroidism
• deficient PTH
  • severe acute hyperphosphatemia
    • tumor lysis syndrome
    • acute renal failure
    • rhabdomyolysis (initial stage)
  • osteitis fibrosa following parathyroidectomy

See also

• Sometimes this condition is confused with hypokalemia.
• Calcium metabolism
• Hypercalcaemia