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Persistence of Vitamin D-deficiency rickets in Toronto in the 1990s

A Binet1, S W Kooh

  • 1Department of Paediatrics, University of Toronto, Ontario.

Insights

Vitamin D deficiency rickets persists in Toronto, primarily affecting infants with dark skin from immigrant families. Exclusive breastfeeding without supplementation and limited sun exposure were key contributing factors.

Area of Science:

  • Pediatrics
  • Nutritional Science
  • Public Health

Background:

  • Vitamin D deficiency rickets is a preventable condition.
  • Recent immigration trends may alter the prevalence of nutritional deficiencies.
  • Dark skin pigmentation reduces cutaneous synthesis of vitamin D.

Purpose of the Study:

  • To describe the clinical characteristics and risk factors of vitamin D deficiency rickets in a Canadian pediatric population.
  • To identify demographic and environmental factors associated with vitamin D deficiency rickets.
  • To inform public health strategies for preventing rickets.

Main Methods:

  • Retrospective chart review of all rickets cases diagnosed between 1988 and 1993 at a children's hospital in Toronto.
  • Analysis of patient demographics, clinical presentation, biochemical and radiographic findings, feeding practices, and environmental exposures.
  • Case series analysis.

Main Results:

  • Seventeen cases of vitamin D deficiency rickets were identified in children aged 7–33 months.
  • All affected children were symptomatic, exhibiting biochemical and radiographic abnormalities, including hypocalcemic seizures in two.
  • Twelve cases involved children of Asian or African origin with dark skin, exclusively breastfed without supplementation and with minimal sun exposure.

Conclusions:

  • Vitamin D deficiency rickets remains an environmental/nutritional disease in Toronto.
  • Targeted prevention efforts should focus on infants with pigmented skin from immigrant families.
  • Public health initiatives should address vitamin D supplementation for breastfed infants and promote adequate sun exposure.

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