title: Increasing incidence of nutritional rickets: a population-based study in Olmsted County, Minnesota.
abstract: OBJECTIVE
  To determine temporal trends in incidence and risk factors of nutritional rickets in a community-based population.
  
  
  METHODS
  Rochester Epidemiology Project data were used to identify all children (aged <18 years) residing in Olmsted County, Minnesota, between January 1, 1970, and December 31, 2009, with diagnostic codes corresponding to rickets, vitamin D deficiency, hypovitaminosis D, rachitis, osteomalacia, genu varum, genu valgum, craniotabes, hypocalcemia, hypocalcemic seizure, and tetany. Record abstraction was performed to select individuals with radiographic confirmation of rickets. Age- and sex-matched controls were identified for the evaluation of risk factors. The main outcome measure was radiographic evidence of rickets without identifiable inherited, genetic, or nonnutritional causes. Incidence rates were calculated using Rochester Epidemiology Project census data.
  
  
  RESULTS
  Of 768 children with eligible diagnostic codes, 23 had radiographic evidence of rickets; of these, 17 children had nutritional rickets. All 17 children were younger than 3 years, and 13 (76%) were of nonwhite race/ethnicity. Clinical presentation included poor growth (n=12), leg deformity (n=8), motor delay (n=5), leg pain (n=3), weakness (n=3), and hypocalcemia or tetany (n=2). The incidence of nutritional rickets in children younger than 3 years was 0, 2.2, 3.7, and 24.1 per 100,000 for the decades beginning in 1970, 1980, 1990, and 2000, respectively (P=.003 for incidence trend). Nutritional rickets was associated with black race, breast-feeding, low birth weight, and stunted growth (P<.05 for all). Four of 13 patients (31%) who underwent 25-hydroxyvitamin D testing had values less than 10 ng/mL.
  
  
  CONCLUSIONS
  Nutritional rickets remains rare, but its incidence has dramatically increased since 2000. Not all cases of rickets can be attributed to vitamin D deficiency.
authors: Department of Family Medicine, Mayo Clinic, Rochester, MN, USA. thacher.thomas@mayo.edu
authors: Tom D
authors: TD
authors: Thacher
authors: Philip R
authors: PR
authors: Fischer
authors: Peter J
authors: PJ
authors: Tebben
authors: Ravinder J
authors: RJ
authors: Singh
authors: Stephen S
authors: SS
authors: Cha
authors: Julie A
authors: JA
authors: Maxson
authors: Barbara P
authors: BP
authors: Yawn
mesh_terms: D015984:Causality; D002675:Child, Preschool; D015897:Comorbidity; D003710:Demography; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000453:epidemiology*; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D010018:Osteomalacia / Q000453:epidemiology*; D012279:Rickets / Q000453:epidemiology*; D012307:Risk Factors; D014808:Vitamin D Deficiency / Q000453:epidemiology*
references: Public Health Rep. 2001 Jul-Aug;116(4):353-61
references: 12037264
references: Am J Clin Nutr. 2008 Dec;88(6):1519-27
references: 19064511
references: Am J Epidemiol. 2011 May 1;173(9):1059-68
references: 21430193
references: N Engl J Med. 1999 Aug 19;341(8):563-8
references: 10451461
references: BMJ. 1999 Jan 2;318(7175):39-40
references: 9872885
references: Arch Dis Child. 2004 Aug;89(8):699-701
references: 15269061
references: J Clin Invest. 2006 Aug;116(8):2062-72
references: 16886050
references: Ann Trop Paediatr. 2006 Mar;26(1):1-16
references: 16494699
references: Clin Pediatr (Phila). 2008 May;47(4):379-84
references: 18192641
references: Am J Clin Nutr. 2004 Dec;80(6 Suppl):1725S-9S
references: 15585795
references: Radiology. 2012 Jan;262(1):234-41
references: 22106354
references: CMAJ. 2007 Jul 17;177(2):161-6
references: 17600035
references: Arch Dis Child. 2006 Jul;91(7):606-7
references: 16595644
references: Arch Dis Child. 2010 Jul;95(7):568-9
references: 20522462
references: Can J Public Health. 2010 Jul-Aug;101(4):I14-8
references: 21033540
references: Pediatrics. 2003 Apr;111(4 Pt 1):908-10
references: 12671133
references: MMWR Morb Mortal Wkly Rep. 1998 Jun 19;47(23):480-2
references: 9649235
references: Pediatrics. 2008 Nov;122(5):1142-52
references: 18977996
references: Pediatrics. 2008 Aug;122(2):398-417
references: 18676559
references: WMJ. 2004;103(5):84-7
references: 15553572
references: Vital Health Stat 11. 2002 May;(246):1-190
references: 12043359
references: Minn Med. 2009 Nov;92(11):43-6
references: 20069998
references: Arch Dis Child. 2011 Aug;96(8):787
references: 21450743
references: J Clin Endocrinol Metab. 2003 Aug;88(8):3539-45
references: 12915633
references: Arch Intern Med. 2009 Mar 23;169(6):626-32
references: 19307527
references: Arch Dis Child. 2006 Jul;91(7):564-8
references: 15956045
references: Arch Pediatr Adolesc Med. 2008 Jun;162(6):505-12
references: 18524739
references: Mayo Clin Proc. 2012 Feb;87(2):151-60
references: 22305027
references: J Fam Health Care. 2011 Mar-Apr;21(2):25-9
references: 21678784
references: Arch Dis Child. 2011 Jul;96(7):694-6
references: 20584848
references: Pediatrics. 2001 Apr;107(4):E45
references: 11335766
references: Am J Clin Nutr. 2004 Dec;80(6 Suppl):1697S-705S
references: 15585790