[Calcium homeostasis in the newborn infant].

The Calcium homeostasis in the perinatal period depends on the changes of the Calcium balance and on the influence of the three Calcium-regulating hormones parathyroid hormone, Calcitonin and 1,25-Dihydroxycholecalciferol. The most common disorder is neonatal hypocalcemia which occurs either as early type (frequent, mainly in prematures) or as late type (rare, probably due to transient hypoparathyroidism).