Objectives: Poor vitamin D status has been reported to be highly prevalent in many non-western immigrant groups living in Norway and other western countries. However, data on rickets are scarce, and the aim of the current study was to identify new cases of nutritional rickets in Norway in the period 2008-2012 among children under the age of 5 years. Design: Register-based cohort study. Setting: The Norwegian population from 2008 to 2012. Participants: Children with nutritional rickets under the age of 5 years. Main outcome measure: Nutritional rickets. Patients with ICD10 (International Statistical Classification of Diseases and Related Health Problems, 10th revision) diagnosis code E55.0 (active rickets) treated at all Norwegian hospitals were identified in the Norwegian Patient Registry. We were able to review 85% of the medical records for diagnosis confirmation. In addition, we identified patients with the diagnoses E55.9, E64.3 and E83.3 to identify individuals with rickets who had been given other diagnoses. Results: Nutritional rickets was confirmed in 39 children aged 0-4 years with the diagnosis of E55.0. In addition, three patients with the diagnosis of unspecified vitamin D deficiency (E55.9) were classified as having nutritional rickets, giving a total of 42 patients. Mean age at diagnosis was 1.40 years (range 0.1-3.5 years), and 93% had a non-western immigrant background. The incidence rate of rickets was estimated to be 0.3 per 10 000 person-years in the total Norwegian child population under the age of 5 years and 3.1 per 10 000 person-years in those with an immigrant background from Asia or Africa. Conclusion: The number of children with nutritional rickets in Norway remained low in the period 2008-2012. Nearly all children had a non-western immigrant background. © 2017 Article author(s) (or their employer(s) unless otherwise stated in the text of the article). All rights reserved.

Immigrant Vitamin D nutrition Rickets

immigrant Asian Norway human child nutrition Cohort Studies Asian continental ancestry group Vitamin D nutritional disorder African rickets Humans migrant Black person African Continental Ancestry Group male Emigrants and Immigrants preschool child female Infant risk factor Risk Factors Child, Preschool newborn clinical article Incidence vitamin D deficiency Article prematurity outcome assessment cohort analysis Norwegian (people) Child