A closer look at rickets and vitamin D deficiency in Manitoba: The tip of the iceberg

Abstract

Objectives: Vitamin D deficiency rickets remains a problem in Canada. Our primary objective was to determine the annual incidence of rickets and/or early vitamin D deficiency in Manitoba. Secondarily, we investigated if there was an increase in the annual incidence. Methods: A retrospective chart review was undertaken to identify cases in our catchment area from 2003 to 2015. Data sources included endocrine and hospital charts and radiology reports. Early vitamin D deficiency was determined by review of all 25(OH)D tests from 2011 to 2015. Values less than 30 nmol/L with an elevated bone marker prompted a chart review in children under 7 years. Results: We identified 46 cases of rickets and 68 with early vitamin D deficiency. For Manitoba, the annual incidence of rickets was 8.2 cases per 100,000 in infants, and 1.6 per 100,000 in children aged 1 to 7 years. Those with early vitamin D deficiency had annual incidences of 2.7 per 100,000 infants and 9.9 per 100,000 Manitoban children. No temporal trends were noted for either. For both disorders, most cases were from northern or rural locales; about 50% were of self-declared Indigenous or Inuit heritage, and the majority (>75%) of children were from families with high material deprivation using area-based socioeconomic measures. Conclusion: Despite several decades of preventative efforts, the incidence of rickets was comparable to previous Canadian reports, particularly in infants. Greater education across the lifespan and engagement with communities and public health agencies will be needed to reduce the high incidence of this preventable disease.

Serum 25-hydroxyvitamin D threshold and risk of rickets in young children: a systematic review and individual participant data meta-analysis to inform the development of dietary requirements for vitamin D

“… NR Ladhani 2004 [ 90 ] UK Case series 65 children, 0–13 years old (mean 2.6 years), with vitamin D deficiency rickets (25OHD < 25 nmol/L and radiologically confirmed rickets), 60% Asian, 37% Afro-Caribbean, 3% European, with ( n = 29) or without ( n = 36) hypocalcemic symptoms. Radioimmunoassay (ImmunoDiagnostic) Lautatzis 2019 [ 91 ] Canada Case series 114 children, 0–16 years (median 30 months), with nutritional rickets ( n = 46) or vitamin D deficiency ( n = 68). Children with 25OHD < 30 nmol/L had radiography.…”

Vitamin D in the prevention of exacerbations of asthma in preschoolers (DIVA): protocol for a multicentre randomised placebo-controlled triple-blind trial

“…Our trial design has incorporated strategies to mitigate risk. We are excluding at enrolment patients at high risk of vitamin D deficiency and are routinely evaluating calcium and vitamin D dietary intake, both to exclude the rare child with rickets (Canadian annual incidence 1.6–2.9/100 000 children),78 79 in whom vitamin D, without calcium, supplementation could lead to hypocalcaemia. In the first hypothetical case of rickets, ALP levels should also be elevated and be a second flag to exclude this child from the study.…”

Nutritional rickets: Historic overview and plan for worldwide eradication

“…The disease was nearly exclusively observed in recently immigrated children or first generation offspring of immigrant parents, with the region of origin predominantly the Indian subcontinent (37%), Africa (33%), and the Middle East (11%). In addition to the general survey on rickets in Canada (Table 4), another evaluation of the annual incidence of rickets in the Manitoba region (Canada) revealed a higher than expected incidence (per 100,000) of 8.2 cases in infants and 1.6 cases in young children (1-7 yrs) [89]. Most of the cases were found in indigenous/Inuit children from poor families.…”