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Canadian Paediatric Surveillance Program
Vitamin D Deficiency Rickets Among Children Living in Canada:
A New Look at an Old Disease
Leanne M Ward1, Isabelle Gaboury1, Moyez Ladhani2 and Stan Zlotkin3. 1Department of Pediatrics, University of Ottawa, Ottawa ON; 2Department of Pediatrics, McMaster University, Hamilton ON; 3Departments of Pediatrics and Nutritional Sciences, University of Toronto, Toronto ON
Presented at the CDA/CSEM in Ottawa, October 2003
Recent literature has proposed that the incidence of Vitamin D deficiency rickets (VDDR) is rising in many countries worldwide. Our clinical experience suggests Canada may be no exception. We sought to determine the incidence of this preventable disease in Canada through the Canadian Pediatric Surveillance Program (CPSP), which provides regular, written contact with 2,300 pediatricians across the country. In the first 6 months of a two-year surveillance program, 33 possible cases of VDDR (defined as calcipenic rickets where the primary etiology is simply dietary vitamin D deficiency) were reported through the CPSP. Twenty cases were confirmed, 15 have been analyzed, 5 were duplicate reports, 2 were discarded for not meeting the case definition, and 6 are presently under review. The majority of confirmed VDDR cases (9/15, 60%) were from Ontario, 20% were from Quebec, and the remaining cases were divided equally among BC, Alberta and Manitoba. Eight of the 15 analyzed cases were female, and the mean age at diagnosis was 1.36±0.60 years. Eighteen percent of the cases had immigrated to Canada in the months preceding diagnosis; 66% percent were of Middle Eastern or Black descent. One case was of Inuit origin, living in the far North of Ontario, while ethnicity for the remaining cases was unknown or not provided. Sixty percent were classified as dark and 40% as intermediate in skin colour. All of the cases had been breast-fed, while none had received vitamin D supplementation. Bowing deformity of the limbs was universal at diagnosis, and 2 patients presented with a fracture. Growth failure, irritability, and delayed gross motor milestones were also reported. Only 11% of mothers had received vitamin D supplementation during pregnancy. Following delivery, none of the mothers had received vitamin D supplementation, and 75% of mothers did not drink milk. Almost half (47%) of the mothers were veiled during and after pregnancy. In summary, the first 6 months of this two-year surveillance study revealed 20 cases of nutritional rickets among infants and toddlers residing in Canada. Intermediate- and dark-skinned children who were breast-fed without vitamin D supplementation were at risk for the disease, and significant morbidity was present at diagnosis in all patients. While there is no question that breast-milk is the ideal fluid source for infants and children, it must be recognized that breast-milk is not a rich source of vitamin D, a fact that becomes particularly important at our northern latitude. We recommend that all breast-fed babies, particularly those who are darker-skinned, receive oral vitamin D supplementation in the first year of life.
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