Hypovitaminosis D in migrant children in Switzerland: a retrospective study

Cholecalciferol (vitamin D-3) 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.

Automated summary

Vitamin D deficiency is prevalent among children in Switzerland, with migrant children at higher risk. The majority of children assessed showed hypovitaminosis D, with the highest prevalence in children from Eastern Mediterranean and African regions.