NPSP<>NPS Pharmaceuticals announces FDA approval of Natpara NPS Pharmaceuticals announced that the U.S. FDA has approved Natpara as an adjunct to calcium and vitamin D to control hypocalcemia in patients with hypoparathyroidism. Hypoparathyroidism is a rare endocrine disorder characterized by insufficient levels of parathyroid hormone, or PTH. Natpara, a bioengineered replica of human PTH, is expected to be available in the second quarter of 2015.