title: Two teenage males with hypocalcemia and elevated parathyroid hormone levels.
abstract: Vitamin D deficiency is not a rare disorder, particularly in minority groups. The Institute of Medicine recommends serum 25-hydroxyvitamin (OH)D levels >20 ng/mL and The Endocrine Society recommends levels >30 ng/mL for good health. In contrast, the 2003-2006 National Health and Nutrition Examination Survey reported average total 25-(OH)D concentrations of 25.6 ± 0.4 ng/mL in whites, 19.5 ± 0.5 ng/mL in Mexican Americans, and 14.8 ± 0.4 ng/mL in blacks. Pediatric patients with vitamin D deficiency may be asymptomatic or may present either with rickets, hypocalcemia, or seizures. Pseudohypoparathyroidism (PHP) is a rare disorder characterized by parathyroid hormone (PTH) resistance with (type 1a) or without (type 1b) the Albright Hereditary Os-teodystrophy (AHO) phenotype of short stature, brachydactyly, and mental retardation. Patients with PHP have elevated PTH levels and may have hyperphosphatemia and hypocalcemia. However, the same laboratory values can be seen in children with vitamin D deficiency, and diagnostic confusion is common. We report two cases of vitamin D deficiency with presentations suggestive of PHP.
authors.affiliation: Department of Pediatrics, Vanderbilt University, Nashville, TN, USA. ashley.h.shoemaker@vanderbilt.edu
authors.forename: Ashley H
authors.initials: AH
authors.lastname: Shoemaker
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Bremer
mesh_terms: D000293:Adolescent; D006801:Humans; D006961:Hyperparathyroidism / Q000175:diagnosis*; D006996:Hypocalcemia / Q000175:diagnosis*; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*
chemical_list: D010281:Parathyroid Hormone