Regulation of plasma levels is by free exchange with body stores, and through the action of hormones such as calcitonin, parathyroid hormone and vitamin D, fibroblast growth factor 23 (FGF23) and phosphate.
Causes of Hypercalcaemia include
- Primary hyperparathyroidism
- Multiple myeloma
- Sarcoidosis
- vitamin D intoxification
- Tuberculosis
- Lithium treatment
- periods of prolonged immobilisation
- acute renal injury
Causes of Hypocalcaemia include
- Inadequate Vitamin D
- Hypoparathyroidism post operatively or post radiotherapy
- Pseudohypoparathyroidism or pseudopseudohypoparathyroidism
- Hyper or hypomagnesemia
- Renal disease : excessive calcium excreted
- End-stage liver disease causing vitamin D inadequacy
- Bone disease – osteomalacia in adults or rickets in children
- Sclerotic metastases
- Genetic causes: congenital absence of parathyroid glands, Di George syndrome, or Fanconi syndrome
- Pancreatitis
- Drugs (eg, rifampicin, antiepileptics, calcitonin, bisphosphonates, calcitonin, corticosteroids, chloroquine)
