Hypovitaminosis D in Migrant Children in Switzerland: a Retrospective Study

Abstract

Cholecalciferol (vitamin D3) is essentially known for its role in the phosphocalcic metabolism and its associated pathologies, such as rickets. In Switzerland, 35 to 50% of children are vitamin D deficient. Due to skin colour, poor nutrition, living conditions and cultural practices, migrant population is particularly at risk. Our aim is to attest the prevalence of hypovitaminosis D in children arriving in Switzerland. We retrospectively assessed 528 children’s vitamin D status and parathyroid hormone, phosphate and calcium levels between 2015 and 2018 by electrochemiluminescence and spectrophotometry. Cholecalciferol was considered insufficient under 50 nmol/L and severely deficient below 25 nmol/L. Seventy-three percent of children showed hypovitaminosis D and 28% had a severe deficiency. Highest prevalence of deficiency was found in children from Eastern Mediterranean (80%) and African regions (75%). Severe deficiency was more prevalent in the South East Asian (39%) and Eastern Mediterranean regions (33%) and more frequent in females. Deficiency was more frequent and more severe in winter. Hypovitaminosis D increased with age. Two children presented with all three biological manifestations associated to severe hypovitaminosis D (hyperparathyroidism, hypocalcaemia and hypophosphatemia). Conclusion: A majority of migrant children presented with hypovitaminosis D. They should be supplemented to prevent complications. A strategy could be to supplement all children at arrival and during wintertime without regular vitamin D level checks. Communicated by Gregorio Paolo Milani * Olivia Fahrni [email protected] Alexandra Wilhelm-Bals [email protected] Klara M. Posfay-Barbe [email protected] Noémie Wagner [email protected] 1 Faculty of Medicine, University of Geneva, Geneva, Switzerland 2 Pediatric Nephrology Unit, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland 3 Pediatric Infectious Diseases Unit, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland What is Known: • Hypovitaminosis D is frequent in children and can lead to bone-related complications. • Migrant children are particularly at risk of deficiency. What is New: • Three-quarters of migrant children evaluated at our migrant clinic in Geneva’s children hospital are deficient in vitamin D, one third severely. • A strategy to correct the deficiency would be to supplement all migrant children at arrival and in winter. European Journal of Pediatrics https://doi.org/10.1007/s00431-021-04143-7