Parathyroid hormone (PTH) and 1,25-(OH) 2 vitamin D play key roles in the regulation of calcium and phosphate balance. Circulating levels of PTH can change within seconds after an alteration in serum calcium. When the serum calcium falls, PTH is rapidly released and acts quickly to promote calcium reabsorption in the distal tubule and the medullary thick ascending limb of Henle's loop. PTH also stimulates the release of calcium from the rapidly exchangeable pool of bone calcium and a chronic elevation in serum PTH increases renal 1,25-(OH) 2 vitamin D production. The presented patient had convulsions and was brought to the hospital when she was 45 days old. Her calcium level was very low but PTH level was only subnormal so she was diagnosed with hypoparathyroidism. We are reporting the case to emphasise that during the evaluation of calcium balance disorders, the PTH level should not be interpreted alone but together with the calcium, phosphate and alkaline phosphates (ALP) levels.
Keywords: Neonatal hypoparathyroidism