Hypocalcaemia occurs in magnesium depletion for several reasons; it can be due to the effects of magnesium deficiency impairing peripheral effects of PTH, and to a decrease in the release of PTH from the parathyroid glands, which may be the most important reason. Patients with hypocalcaemia due to magnesium depletion cannot be adequately treated until the magnesium deficiency is corrected.
